Can Web Scraping Be Detected
How To Scrape A Website Without Getting Blacklisted
Website scraping is a technique used to extract large amounts of data from web pages and storing them on your computer. The data on the websites can only be viewed using a web browser, and it cannot be saved for your personal use. The only way to do that is to copy and paste it manually, which can be a tedious task. This whole process can be automated using web scraping techniques. Using an advanced infrastructure like the SERP API, you can scrape the data successfully. You can also build your own web ChoudharyA Digital Nomad Embracing Change! Website scraping is a technique used to extract large amounts of data from web pages and storing them on your computer. It could take hours or even days to complete the ever, this whole process can be automated using web scraping techniques. You don’t need to copy and paste the data manually; instead, you can use web scrapers to finish the task within a small amount of time. If you already know what scraping is, then chances are you know how helpful it can be for marketers and organizations. It can be used for brand monitoring, data augmentation, tracking latest trends, sentiment analysis to name a are a lot of scraping tools available which you can use for web-based data collection. However, not all those tools work efficiently as search engines do not want scrapers to extract data from its result pages. But using an advanced infrastructure like the SERP API, you can scrape the data successfully. Other tools like scrapy, parsehub provides an infrastructure to scrape the data by completely mimicking human behavior these tools are quite beneficial, but they are not entirely free for use. You can also build your own web scraper. But keep in mind, you have to be very smart about it. Let’s talk about some tips to avoid getting blacklisted while scraping the RotationSending multiple requests from the same IP is the best way to ruin you get blacklisted by the websites. Sites detect the scrapers by examining the IP address. When multiple requests are made from the same IP, it blocks the IP address. To avoid that, you can use proxy servers or VPN which allows you to route your requests through a series of different IP addresses. Your real IP will be masked. Therefore, you will be able to scrape most of the sites without a SlowlyWith scraping activities, the tendency is to scrape data as quickly as possible. When a human visits a website, the browsing speed is quite slow as compared to crawlers. Thus, websites can easily detect scrapers by tracking access speed. If you’re going through the pages way too fast, the site is going to block you. Adjust the crawler to optimum speed, add some delays once you’ve crawled a few pages, and put some random delay time between your requests. Do not slam the server, and you’re good to Different Scraping PatternsHumans browse websites differently. There is a different view time, random clicks, etc. when users visit a site. But the bots follow the same browsing pattern. Websites can easily detect scrapers when they encounter repetitive and similar browsing behavior. Therefore, you need to apply different scraping patterns from time to time while extracting the data from the sites. Some sites have a really advanced anti-scraping mechanism. Consider adding some clicks, mouse movements, etc. to make the scraper look like a Not Fall For Honeypot TrapsA honeypot is a computer security mechanism set up to detect the scrapers. They are the links which are not visible to the users and can be found in the HTML code. So, they are only visible to web scrapers. When a spider visits that link, the website will block all the requests made by that client. Therefore, it is essential to check for the hidden links on a website while building a sure that the crawler only follows links which have proper visibility. Some honeypot links are cloaked using the same color on the text as that of the background. The detection of such traps is not easy, and it will require some programming skills to avoid such User AgentsA User-Agent request header consists of a unique string which helps to identify the browser being used, its version, and the operating system. The web browser sends the user-agent to the site every time a request is being made. Anti-scraping mechanisms can detect bots if you make a large number of requests from a single user agent. Eventually, you will be blocked. To avoid this situation, you should create a list of user-agents and switch the user agent for each request. No site want to block genuine users. Using popular user agents like Googlebot can be helpful. Headless BrowserSome websites are really hard to scrape. They detect browser extensions, web fonts, browser cookies, etc. to check whether the request is coming from a real user or not. If you want to scrape such sites, you will need to deploy a headless browser. Tools like Selenium, PhantomJS are a few options that you can explore. They can be a bit hard to set up but can be very helpful in these tips can help you refine your solutions, and you will be able to scrape the websites without getting blocked. TagsJoin Hacker Noon Create your free account to unlock your custom reading experience.
Can page scraping be detected? – Stack Overflow
So I just created an application that does page scraping for me, and ran it. It worked fine. I was wondering if someone would be able to figure out that the code was being page scraped, whether or not they had written code for that purpose?
I wrote the code in java, and it’s pretty much just checking for one line of the html code.
I thought I’ld get some insight on that before I add anymore code to this program. I mean it’s useful, and all, but it’s almost like a hack.
Seems like the worst case scenario as a result of this page scraper isn’t too bad as I can just use another device later and the IP will be different. Also it might not matter in a month. The website seems to be getting quite a lot of web traffic anyways at the moment. Whoever edits the page is probably asleep now, and it really hasn’t accomplished anything at this point so this could go unnoticed.
Thanks for such fast responses. I think it might have gone unnoticed. All I did was copy a header, so just text. I guess that is probably similar to how browser copy-paste works. The page was just edited this morning, including the text I was trying to get. If they did notice anything, they haven’t announced it, so all is good.
asked Aug 4 ’11 at 5:09
Slayer0248Slayer02481, 1733 gold badges14 silver badges25 bronze badges
2
It is a hack. 🙂
There’s no way to programmatically determine if a page is being scraped. But, if your scraper becomes popular or you use it too heavily, it’s quite possible to detect scraping statistically. If you see one IP grab the same page or pages at the same time every day, you can make an educated guess. Same if you see requests on another timer.
You should try to obey the file if you can, and rate limit yourself, to be polite.
answered Aug 4 ’11 at 5:12
Daniel LyonsDaniel Lyons21. 7k2 gold badges50 silver badges74 bronze badges
1
As a sysadmin myself, yes I’d probably notice but ONLY based on the behavior of the client. If a client had a weird user agent, I’d be suspicious. If a client browsed the site too quickly or in very predictable intervals, I’d be suspicious. If certain support files were never requested (, various linked in CSS and JS files), I’d be suspicious. If the client were accessing odd (not directly accessible) pages, I’d be suspicious.
Then again I’d have to actually be looking at my logs. And this week Slashdot has been particularly interesting, so no I probably wouldn’t notice.
answered Aug 4 ’11 at 5:20
Chris EberleChris Eberle45. 8k12 gold badges77 silver badges114 bronze badges
0
It depends on how have you implemented this and how smart are the detection tools.
First take care about User-Agent. If you do not set it explicitly it will be something like “Java-1. 6”. Browsers send their “unique” user agents, so you can just mimic the browser behavior and send User-Agent of MSIE, or FireFox (for example).
Second, check other HTTP headers. Probably some browsers send their specific headers. Take one example and follow it, i. e. try to add the headers to your requests (even if you do not need them).
Human user acts relatively slowly. Robot may act very quickly, i. retrieve the page and then “click” link, i. perform yet another HTTP GET. Put random sleep between these operations.
Browser retrieves not only the main HTML. Then it downloads images and other stuff. If you really do not want to be detected you have to parse HTML and download this stuff, i. actually be “browser”.
And the last point. It is obviously not your case but it is almost impossible to implement robot that passes Capcha. This is yet another way to detect robot.
Happy hacking!
answered Aug 4 ’11 at 5:24
AlexRAlexR111k14 gold badges121 silver badges197 bronze badges
If your scraper acts like a human then there is a hardly any chance for it to be detected as a scraper. But if your scraper acts like a robot then its not difficult to be detected.
To act like a human you will need to:
Look at what a browser sends in the HTTP headers and simulate them.
Look at what a browser requests for when accessing the page and access the same with the scraper
Time your scraper to access at the speed of a normal user
Send requests at random intervals of time instead of at fixed intervals
If possible make requests from a dynamic IP rather than a static one
answered Aug 4 ’11 at 5:25
manubkkmanubkk1, 43812 silver badges19 bronze badges
assuming you wrote the page scraper in a normal manner, i. e., it fetches the whole page and then does pattern recognition to extract what you want from the page, all someone might be able to tell is that the page was fetched by a robot rather than a normal browser. all their logs will show is that the entire page was fetched; they can’t tell what you do with it once it’s in your RAM.
answered Aug 4 ’11 at 5:13
jcomeau_ictxjcomeau_ictx35. 7k6 gold badges90 silver badges101 bronze badges
To the server serving the page, there’s no difference whether you download a page into the browser or download a page and screen scrape it. Both actions just require an HTTP request, whatever you do with the resulting HTML on your end is none of the server’s business.
Having said that, a sophisticated server could conceivably detect activity that doesn’t look like a normal browser. For example, a browser should request any additional resources linked to from the page, something that usually doesn’t happen when screen scraping. Or requests with an unusual frequency coming from a particular address. Or simply the HTTP User-Agent header.
Whether a server tries to detect these things or not depends on the server, most don’t.
answered Aug 4 ’11 at 5:15
deceze♦deceze481k78 gold badges684 silver badges835 bronze badges
I’d like to put my two cents in for others that may be reading this. In the past couple of years web scraping has been frowned upon more and more by the court system. I’ve cited a lot of examples in a blog post I recently wrote.
You should definitely abide the but also look at the websites T&C’s to make sure you are not in violation. There are definitely ways that people can identify you are web scraping and there could be potential consequences for doing so. In the event that web scraping is not disallowed by the website’s Terms and Conditions, then have fun but make sure to still be conscionable. Dont destroy a webserver with an out of control bot, throttle yourself to make sure you dont impact the server!
For full disclosure, I am a co-founder of Distil Networks and we help companies identify and stop web scrapers and bots.
answered Oct 21 ’13 at 16:13
RamiRami1, 0008 silver badges7 bronze badges
Not the answer you’re looking for? Browse other questions tagged java html web-scraping or ask your own question.
Is Web Scraping Illegal? Depends on What the Meaning of the Word Is
Depending on who you ask, web scraping can be loved or hated.
Web scraping has existed for a long time and, in its good form, it’s a key underpinning of the internet. “Good bots” enable, for example, search engines to index web content, price comparison services to save consumers money, and market researchers to gauge sentiment on social media.
“Bad bots, ” however, fetch content from a website with the intent of using it for purposes outside the site owner’s control. Bad bots make up 20 percent of all web traffic and are used to conduct a variety of harmful activities, such as denial of service attacks, competitive data mining, online fraud, account hijacking, data theft, stealing of intellectual property, unauthorized vulnerability scans, spam and digital ad fraud.
So, is it Illegal to Scrape a Website?
So is it legal or illegal? Web scraping and crawling aren’t illegal by themselves. After all, you could scrape or crawl your own website, without a hitch.
Startups love it because it’s a cheap and powerful way to gather data without the need for partnerships. Big companies use web scrapers for their own gain but also don’t want others to use bots against them.
The general opinion on the matter does not seem to matter anymore because in the past 12 months it has become very clear that the federal court system is cracking down more than ever.
Let’s take a look back. Web scraping started in a legal grey area where the use of bots to scrape a website was simply a nuisance. Not much could be done about the practice until in 2000 eBay filed a preliminary injunction against Bidder’s Edge. In the injunction eBay claimed that the use of bots on the site, against the will of the company violated Trespass to Chattels law.
The court granted the injunction because users had to opt in and agree to the terms of service on the site and that a large number of bots could be disruptive to eBay’s computer systems. The lawsuit was settled out of court so it all never came to a head but the legal precedent was set.
In 2001 however, a travel agency sued a competitor who had “scraped” its prices from its Web site to help the rival set its own prices. The judge ruled that the fact that this scraping was not welcomed by the site’s owner was not sufficient to make it “unauthorized access” for the purpose of federal hacking laws.
Two years later the legal standing for eBay v Bidder’s Edge was implicitly overruled in the “Intel v. Hamidi”, a case interpreting California’s common law trespass to chattels. It was the wild west once again. Over the next several years the courts ruled time and time again that simply putting “do not scrape us” in your website terms of service was not enough to warrant a legally binding agreement. For you to enforce that term, a user must explicitly agree or consent to the terms. This left the field wide open for scrapers to do as they wish.
Fast forward a few years and you start seeing a shift in opinion. In 2009 Facebook won one of the first copyright suits against a web scraper. This laid the groundwork for numerous lawsuits that tie any web scraping with a direct copyright violation and very clear monetary damages. The most recent case being AP v Meltwater where the courts stripped what is referred to as fair use on the internet.
Previously, for academic, personal, or information aggregation people could rely on fair use and use web scrapers. The court now gutted the fair use clause that companies had used to defend web scraping. The court determined that even small percentages, sometimes as little as 4. 5% of the content, are significant enough to not fall under fair use. The only caveat the court made was based on the simple fact that this data was available for purchase. Had it not been, it is unclear how they would have ruled. Then a few months back the gauntlet was dropped.
Andrew Auernheimer was convicted of hacking based on the act of web scraping. Although the data was unprotected and publically available via AT&T’s website, the fact that he wrote web scrapers to harvest that data in mass amounted to “brute force attack”. He did not have to consent to terms of service to deploy his bots and conduct the web scraping. The data was not available for purchase. It wasn’t behind a login. He did not even financially gain from the aggregation of the data. Most importantly, it was buggy programing by AT&T that exposed this information in the first place. Yet Andrew was at fault. This isn’t just a civil suit anymore. This charge is a felony violation that is on par with hacking or denial of service attacks and carries up to a 15-year sentence for each charge.
In 2016, Congress passed its first legislation specifically to target bad bots — the Better Online Ticket Sales (BOTS) Act, which bans the use of software that circumvents security measures on ticket seller websites. Automated ticket scalping bots use several techniques to do their dirty work including web scraping that incorporates advanced business logic to identify scalping opportunities, input purchase details into shopping carts, and even resell inventory on secondary markets.
To counteract this type of activity, the BOTS Act:
Prohibits the circumvention of a security measure used to enforce ticket purchasing limits for an event with an attendance capacity of greater than 200 persons.
Prohibits the sale of an event ticket obtained through such a circumvention violation if the seller participated in, had the ability to control, or should have known about it.
Treats violations as unfair or deceptive acts under the Federal Trade Commission Act. The bill provides authority to the FTC and states to enforce against such violations.
In other words, if you’re a venue, organization or ticketing software platform, it is still on you to defend against this fraudulent activity during your major onsales.
The UK seems to have followed the US with its Digital Economy Act 2017 which achieved Royal Assent in April. The Act seeks to protect consumers in a number of ways in an increasingly digital society, including by “cracking down on ticket touts by making it a criminal offence for those that misuse bot technology to sweep up tickets and sell them at inflated prices in the secondary market. ”
In the summer of 2017, LinkedIn sued hiQ Labs, a San Francisco-based startup. hiQ was scraping publicly available LinkedIn profiles to offer clients, according to its website, “a crystal ball that helps you determine skills gaps or turnover risks months ahead of time. ”
You might find it unsettling to think that your public LinkedIn profile could be used against you by your employer.
Yet a judge on Aug. 14, 2017 decided this is okay. Judge Edward Chen of the U. S. District Court in San Francisco agreed with hiQ’s claim in a lawsuit that Microsoft-owned LinkedIn violated antitrust laws when it blocked the startup from accessing such data. He ordered LinkedIn to remove the barriers within 24 hours. LinkedIn has filed to appeal.
The ruling contradicts previous decisions clamping down on web scraping. And it opens a Pandora’s box of questions about social media user privacy and the right of businesses to protect themselves from data hijacking.
There’s also the matter of fairness. LinkedIn spent years creating something of real value. Why should it have to hand it over to the likes of hiQ — paying for the servers and bandwidth to host all that bot traffic on top of their own human users, just so hiQ can ride LinkedIn’s coattails?
I am in the business of blocking bots. Chen’s ruling has sent a chill through those of us in the cybersecurity industry devoted to fighting web-scraping bots.
I think there is a legitimate need for some companies to be able to prevent unwanted web scrapers from accessing their site.
In October of 2017, and as reported by Bloomberg, Ticketmaster sued Prestige Entertainment, claiming it used computer programs to illegally buy as many as 40 percent of the available seats for performances of “Hamilton” in New York and the majority of the tickets Ticketmaster had available for the Mayweather v. Pacquiao fight in Las Vegas two years ago.
Prestige continued to use the illegal bots even after it paid a $3. 35 million to settle New York Attorney General Eric Schneiderman’s probe into the ticket resale industry.
Under that deal, Prestige promised to abstain from using bots, Ticketmaster said in the complaint. Ticketmaster asked for unspecified compensatory and punitive damages and a court order to stop Prestige from using bots.
Are the existing laws too antiquated to deal with the problem? Should new legislation be introduced to provide more clarity? Most sites don’t have any web scraping protections in place. Do the companies have some burden to prevent web scraping?
As the courts try to further decide the legality of scraping, companies are still having their data stolen and the business logic of their websites abused. Instead of looking to the law to eventually solve this technology problem, it’s time to start solving it with anti-bot and anti-scraping technology today.
Get the latest from imperva
The latest news from our experts in the fast-changing world of application, data, and edge security.
Subscribe to our blog
Frequently Asked Questions about can web scraping be detected
Are web scrapers detectable?
7 Answers. There’s no way to programmatically determine if a page is being scraped. But, if your scraper becomes popular or you use it too heavily, it’s quite possible to detect scraping statistically. If you see one IP grab the same page or pages at the same time every day, you can make an educated guess.Aug 4, 2011
Can you get in trouble for web scraping?
Web scraping and crawling aren’t illegal by themselves. … Web scraping started in a legal grey area where the use of bots to scrape a website was simply a nuisance. Not much could be done about the practice until in 2000 eBay filed a preliminary injunction against Bidder’s Edge.
How do you not get caught web scraping?
Steps: Find a free proxy provider website. Scrape the proxies. Check the proxies and save the working ones. Design your request frequencies (try to make it random) Dynamically rotate the proxies and send your requests through these proxies. Automate everything.Feb 2, 2020
