Why do fansubbed animes have a reminder to not sell their fansubbed product? Sometimes they have the following reminder during the show:
This is a free fansub: not for sale, rent, or auction
I was wondering why that was necessary. Is it so that they do not get into legal problems? What is the purpose of that reminder?
I think it's a combination of a few factors.
First, there's a sort of ethical code among some fansubbers that dictates that they fansub for "the love of anime" or something to that effect, and that it's improprietous to profit off of fansubbing. I'm not sure how effective a reminder of this sort would be to people who don't subscribe to the same ethical code (i.e. the people at whom this message would be targeted), but there you have it. Sticking a reminder on your fansubs is pretty much a no-cost endeavor, so it's not like it can hurt.
Then, there's the belief that explicitly stating that you do not intend to profit off of your fansubs makes you less liable for copyright infringement. I doubt this has been tested (I don't know of any litigation against fansubbers), but I rather doubt this would be of much value as a legal defense - statutory damages (as opposed to actual damages) are available in USA copyright infringement cases under federal law (and, I imagine, in other jurisdictions as well).
I suspect (but have no evidence) that this is a holdover from the pre-Internet days of fansub distribution when you actually needed to pass around video tapes to get your anime fix. Exchanging physical materials is likely to get you more scrutiny from law enforcement than exchanging digital information, and this relates to my previous point: infringing copyright is bad, but profiting off of infringed copyrights is probably worse, or at least that's the general perception. C. Griffin's answer to this question contains an interesting view on the matter, from the perspective of someone who consumed fansubs in pre-internet times.
Adam Davis also brought up in a comment another point I meant to address - fansubbers don't want other people profiting off of their work - it's kind of a slap in the face. So what's one way to do that? Stick a big "this is not for sale" warning on it, kind of like how a lot of free (gratis) software comes with a notice saying something like "if you paid for this, you should ask for your money back because this is free software".
So here's the problem: basically all fansubbing these days is done with "softsubs" - that is, the subtitles are basically a text file that accompanies a video. It's dead easy to edit these things (particularly using software like Aegisub), so this is probably another reason that you don't see these disclaimers anymore: they're easy to remove. In the pre-softsub days (maybe before 2008~2010 or so? I don't have my chronology down for this very well), subtitling was done by re-encoding the video to have the subtitles ("hardsubs") baked into the video file. Since this is much more difficult to alter, disclaimers would have been more permanent (and hence, useful) back then.
Anyway, I haven't seen a disclaimer of this sort on any fansubs from at least the past five years or so - it's gone the way of the dinosaurs. In the modern fansubbing world, where all exchange of fansubs is electronic and hardsubs are obsolete, these disclaimers serve no actual purpose.
(I have seen this sort of thing on recent manga scanlations, though - but that's a topic for another question. The key difference here, I suspect, is that scanlations are still "hardsubbed", so to speak.)
I was a consumer of fansubs in the early-mid 90's. This statement has no bearing on my answer, however, I was pointing it out because someone thought it would be interesting to hear from a pre-Internet fansub consumer.
All of these answers are valid. Ultimately, the fan sub groups need legal authorities to know that profit is not expected or accepted. It's a gray area, because the two "products" that we're discussing are the original work (included in a fan sub), and then the translation itself. The translation can probably be distributed freely, as it is not the same as the original dialogue -- and on its own is an interpretation of a story by a translator.
The iffy part is about the original work being distributed. In most countries, it is illegal to distribute (user-made) copies of copyrighted work without express written consent of the copyright holder. It robs the copyright holder of earnings, blah blah blah. I'm not a legal zealot, and I'm not here to defend any particular side. However, in this day and age, the copyright protections are expected to be upheld in the international community, and enforced by local government or at a higher level -- Interpol. We don't normally hear about busts like this, because a fansubber usually has a small audience, and many studios secretly find this type of behavior beneficial to increasing their products popularity, and with any luck, profitability.
Footnote about the pre-Internet days: We would mail our brand new blank VHS cassettes to fansub groups in postage-paid envelopes so that no money would exchange hands whatsoever. It might take a month or two to get your tapes, but for foreign video that was unreleased domestically, it's what you had to do. </backinthedaystories>
Even though in some countries, translations of original works are considered original works themselves, the copyright laws are still pretty vague, and so to avoid getting in trouble, fansub groups add such reminders that could be interpreted as "we did not intend to infringe any rights" if they get sued.
So if some shady guy tries to sell some dvds, and they contain very explicit markings of a certain fansub group, that group has some protection by stating that they did not intend for that to happen.
I think this is largely to do with Copyright issues. You see those who distribute or offer the file are usually in the wrong and violate Japanese copyright laws. But because copyright highly relies on where you are in the world (speaking geographically) fan operated groups who do these fansubs often get away from this and find a way to "turn the other corner".
Even though it is possible to find loopholes such as this, these warnings are often meant to redirect blame if they are sued for infringing on copyright.
I have seen notices that warn that if you have paid money for this fansub you have been ripped off leading me to believe that there have been cases of other parties trying to make money by selling free fansubs and these notices are attempts to stop that.
