My stance is that these websites are a great boon to the research community and they were certainly extremely helpful for my research. I think they should be applauded rather than persecuted, and while they may be illegal now, I think a way to make them legal should be found (in the same way I can download articles legally through my university's subscription to all the major publishers and journals).
Can I thank them in the acknowledgements section of my thesis?
You can thank whomever you want in the acknowledgments of your thesis, but there may be consequences that you have to live with.
In my opinion it is a bad idea to admit to illegal activity in a formal document like this. Once you write that, you cannot unwrite it: it will be archived for the rest of your career. I don't really think you'd get in any trouble directly, but by doing so you're advertising the fact that you are willing to break rules that you don't like and do so entirely openly. I think that a lot of potential employers prefer employees who when they break the rules for a good reason, do so more quietly.
I also don't really see what you're gaining by doing this. A thesis acknowledgment is not a step toward legal free downloading of texts. I happen to agree with you that "a way to make them legal should be found". One way I work towards this is that I make all of my lecture notes -- some of which are very close to being textbooks -- freely available on the internet. Whenever I have spoken with publishing companies, I mention at the first meeting my requirement that my material be made freely available on the internet. To my surprise, they have not walked out of the room. I also have largely stopped assigning expensive required texts.
In summary: an acknowledgment to the providers of illegal content is a microscopic flouting of the establishment, not a helpful act. I recommend that you think a bit more carefully about what you can do to actually improve the situation.
I had a similar problem in my ethics class but I approached it differently. My argument was that piracy forces legal content providers to provide better services. I’m not going to drill down on that as it’s a much bigger topic. Thanking piracy for illegal but freely available information isn’t ideal as it sounds like you're endorsing it. In a scholarly context, that’s not overtly wrong but it’s not ethical. Debating that with professor’s and/or ethics boards is radically different than here or with your peers.
Thanking piracy for forcing legal content providers to provide better services is better. That way you can structure arguments around what drives business change for the better. You can focus more on liking the end result without directly endorsing piracy. That might seem like dodging the issue a bit but I wasn’t comfortable directly thanking piracy in the context of my ethics class.
In the context of learning and freely available information, I think we’re all a little torn. I love the idea of all college level information being freely available to everyone but that’s not feasible. Someone has to put together that information. Someone has to help others understand that information. If actual books are being made there’s a production cost. Everything that goes into producing that information has a cost be it in time or money. It easy to think of free/piracy as a great idea but it’s usually sharing that end product that had a cost to produce, for free. If it was just shared for free no money would be made to cover the costs of producing that information. Why would anyone produce information if they lose time and money? They wouldn’t. Then there wouldn’t be that great information to pirate.
On the other hand, the legitimate cost of that information is very high. For a country with over a trillion in student loan debt, is more debt the right answer to get people trained and into the workforce?
As a counterpoint to the other answers, I'd say you should absolutely thank these websites. Why?
That being said, phrasing and tact are everything. Make it subtile and keep it focused on the cause and not the disobediance. Something like
"I'd like to thank those who have provided open access to otherwise prohibitively expensive material."
is better than
"A big shout-out to all the all the pirates out there! @#ck The Man!"
You're probably not going to get a lot of respect by sounding like an anarchist.
NOTE: I may have a biased point of view, given that I'm in a field where most researchers equate paywalls with extortion and all our most prestigious journals are free. If a subscription to the the top journal in your field costs thousands of dollars a year and your colleagues are OK with that, I'm not sure what to tell you.
Since this move is politically risky, should you take the risk? Richard Hamming addresses the general point in the famous You and Your Research when he talks about ego assertion. The discussion is worth reading—let me quote just the following:
And I think John Tukey paid a terrible price needlessly. He was a genius anyhow, but I think it would have been far better, and far simpler, had he been willing to conform a little bit instead of ego asserting.
What was the ego assertion there? Funnily, it was just dressing casually instead of formally—these were the '50s.
Also, there are better ways to fight for the cause, like joining one of the movements for changing publication models—legally. (See open access, though that's mainly for papers). Any actual work in such a movement could even go (I guess) in your CV as community service.
I think there are more cons than pros to writing this in your acknowledgement. To me it seems more like a written declaration claiming that you participated in some illegal activity. Many in the academic community write books which are pirated and they probably will not take it well if they read that in your PhD thesis. If you plan on pursuing a career in academia, these people will probably be a thorn in your side. Also, if you are in a graduate program where you submit a thesis before you defend it. Your defense committee may decide to give you a hard time during your defense (of course I understand that in some graduate programs you may not have any other exams left after you submit your thesis).
All I'm saying is that it may cause you much pain without contributing to your cause.
No its not okay to knowingly receive stolen property and thank the thieves. If the information provided in the reference was relative to your work, and you are receiving a degree because it helped you to so so, then thank the authors who created this work and took the time to write it down and get it published by buying their book. And next time please find a valid library and borrow a legal copy.
As a publisher and author I would be extremely annoyed that someone actively promotes those who commit the criminal offence of illegally copying and distributing our intellectual property.
First, I would refer to your university that your research was conducted using illegal obtained materials: that is undoubtedly in breach of your contract with the university and I would press for the cancellation of your degree. Harsh? Yes, but you are a criminal benefiting from the knowledge, expertise and labours of others.
Secondly, I would take steps to have the site removed from major search engines and references to it blocked. We routinely do that now, when we become aware of them. We refer the site hosts to the relevant authorities in the countries where they are hosted with a view to having the site taken down and the owners / operators prosecuted.
We would publicise the internet host and its IP range with a view to responsible site owners blocking that host's customers from accessing websites around the world.
And finally, we would publicise your name and that you were prepared to use criminally sourced material for your own advancement, demonstrating both a tendency to criminality and that you operate in a moral vacuum, in the hope that no employer would engage a person with such a lack of ethical values.
If the book you want is not legally available on-line, go to a proper library where publishers and authors are rewarded for loans. See if the book is available for lending for Kindle (you pay a small membership fee) because, again, publishers and authors are paid when you borrow.
Would you thank the photocopy shop that makes illegal copies of text books?
No, because you know it's a crime.
