[fencepost]

Ignoring/bypassing robots.txt is probably a bad idea unless you're going to never even look for it and are going to try to plead incompetence if someone comes after you.

In the early stages you probably won't be robots.txt'd because you're insignificant.

In later stages, you're hoping to not be robots.txt'd because you're providing a worthwhile service not just for users but for the site.

At neither stage should you force companies that want you not indexing their content to go beyond basic means (robots.txt) because the more serious measures are all going to cost them more money (tracking / blocking your IPs, C&D, DMCA requests to your provider requesting that the entire site be taken down because there are thousands of infringing items, lawsuits seeking (damages | court costs | costs for dealing with your circumvention of technical measures to keep you out of the site), finding of friendly prosecutors, etc.).

You don't want to go down that more expensive road.

[runbycomment]

Also worth mentioning: as long as you're scraping facts and combining them in a novel way, copyright law is much less relevant.

This opeartes in what I consider a legal grey area. Don't make it obvious that you're scraping, only scrape public information, transform the results, proxy your requests, all contribute to lowering the legal profile (which is my only concern, as I feel I am acting within my own ethical limits).

[anseljh]

Eek. This is only kinda true. You ought to talk to a copyright lawyer and get a handle on derivative works and data compilations. You can get started by reading this Supreme Court case:

Feist Publications, Inc. v. Rural Tel. Service Co., 499 U.S. 340 (1991) https://casetext.com/case/feist-publications-inc-v-rural-tel...

Disclaimer: IAAL but IANYL.

[runbycomment]

In your opinion, how much of that situation's complexity is eliminated simply by scraping the Google cache of a site?

I also wonder how possible it is to hide behind proxies, especially if they are owned by entities in other countries. If a site I'm scraping is unable to identify who does the scraping, it seems difficult for them to prove "this guy uses our data and must be scraping us".

[fencepost]

The more you have to jump through hoops to get the data (or hide that you're getting it or that you're the one getting it), the more it sounds like doing this for the wrong reasons.

Also, since this is presumably something you're going to be doing as a hobby (money creates trails), the unfortunate reality is that "right" and "wrong" in copyright law matter much less than "Oh crap, I'm being sued for $500k in $further_away(New York|California), how do I defend this?" That's why you don't ignore the polite way of saying "go away" which is robots.txt or the rude way which is a C&D - if a lawsuit (the mean way) is the first communication you have from a company, odds are pretty good that an attorney can help because judges are busy and don't want lawsuits to be the first thing unhappy companies try.

[runbycomment]

I understand what you're saying, we just come from very different perspectives. Most of my results are after significant transformation and combination, resulting in models to test against. I'm not very concerned with copyright violation, as I rarely (never?) re-publish copyrighted information.

Have there been any court cases where a person scraping public information has been found in the wrong? I know of the LinkedIn case from Jan 2014, but in that case the offenders were creating LI accounts to scrape private information. I believe that Craigslist lost it's case against e.g. padmapper, didn't they?

While I respect what you're saying in your first sentence, I view it differently. Setting aside the legal issues, I see it as someone trying to control use in a public space. I don't consider that a valid reason -- if it's public, I can consume it. Avoiding detection is a reaction to sites trying to create rules that I interpret as invalid.

If a company tried to block off a public road without legal backing, I would consider it not only my right but also my duty to traverse that road. [mediocre analogy, but it does represent my opinion fairly accurately.]

[fencepost]

The things that jump out at me there are "that I interpret as invalid" and "Have there been any court cases where a person scraping public information has been found in the wrong?"

Tackling the second one first, I'd like to rephrase that: "Have all the court cases where a person was scraping public information been found in their favor and they were awarded all attorney fees and expenses?"

As far as "that I interpret as invalid" the courts exist to decide between varying interpretations of rights and laws. I've never heard that "inexpensively" was expected to be part of that description. I'm not saying that you're wrong - I'm just saying that there's a significant difference between "I'm taking on a coding and data analysis project" and "I'm taking on a coding and data analysis project with a big helping of legal distractions."

I'm not fully up on the Craigslist vs padmapper/3taps case - was it ever actually fully decided? And how much did fighting that case cost 3taps? Looking at the statement on their website it doesn't sound all that victorious, and I can't help but suspect that even ignoring whatever financial impact there was the distraction and demands of the case must have had a serious effect on any projects 3taps was working on (or considering and back-burnering) during that time.

As a counterexample since you said you were going to be keeping and displaying thumbnails, I'll toss out the artwork from "Kind of Bloop" (see http://waxy.org/2011/06/kind_of_screwed/) which was a highly-pixelated (and maybe only 8-color?) transformation of a photo of Miles Davis. TL;DR, Andy Baio ended up paying ~$32k to settle the case not because he thought he was wrong but because it was the least expensive option.

I'm not saying don't do it - I'm just saying that you should go into it with your eyes open and don't do things that will exacerbate any non-technical problems you may run into. That may be a chilling effect, but at least you can bring a coat.

[fredophile]

Your public road analogy is very wrong. A better analogy would be a private road with a sign saying "Google streetview welcome. runbycomment stay out." Would you feel entitled to drive down the private road? Would the owner allowing Google to drive down the road make you feel entitled to do it?

We aren't discussing a public space. We're talking about a private server. They pay for hosting and bandwidth. Why do you feel entitled to use it?

[pnathan]

Why is ignoring robots.txt a bad idea? The information's being made publicly accessible...

[fencepost]

For the crass and practical reason, because A) Anyone can sue for anything (caveat: as long as it's not so egregiously stupid as to get them slapped down by a judge) B) techies' definitions of "egregiously stupid" and judges' definitions of "egregiously stupid" may not have very much overlap

As a simple example imagine that the owner of a local shop REALLY didn't like you to the extent that he had his door painted with six-inch letters at eye level "PNathan KEEP OUT!" It's a publicly accessible shop, but if you walk in and he calls the police, will your having ignored that sign make a difference in their interactions with you? How about if you've both ignored that sign and come in wearing a disguise?

[kluck]

I like the analogy.

> ...will your having ignored that sign make a difference in their interactions with you?

For sure.

> How about if you've both ignored that sign and come in wearing a disguise?

Not if he finds out. But the disguise will make it even worse if he does find out.

So it boils down to: Can you hide yourself good enough to not beeing detected (includes beeing detected by showing information that is presumably crawled rather than detecting the process of crawling)? It is a risk that you may take by weighting assumed loss (court case) and gain (money from using crawled data).

I may add: A clever "data provider" will inject some hidden beacons into their data that makes it easy for them to later detect that data in other websites. So actually you can always be detected, because you must have crawled that data from them.