Is it legally possible to use a Free Software liscence for forum content. The goal here is to “free” all the content that has been produced on the forum. Given that users don’t sign of check any legal agreement I’m not sure that would be possible.
If you don’t think that would be possible, how do you think I could make most of the forum content GPL or “free” for anybody to use? By post basis? By user basis?
Any advice would be appreciated.
Custom user field where the user agrees to license his content? Since it shows on the user sign up field you can put a field there.
The correct answer here is to consult with a lawyer licenced to practice in your jurisdiction (or whichever jurisdiction will be the relevant one for the forum’s legal operation) who specialises in online copyright matters. Only they’ll be able to confirm exactly how it needs to be done to have the full protection of the law.
However, if that is beyond your resources, I’d suggest taking a look at exactly how Stack Exchange does it. They have a policy that all user-contributed content is CC-BY-SA. I would presume that, at some point, competent legal advice was sought to ensure that they were doing things in a legally defensible way. Certainly, given how much VC they’ve taken, I’d expect that at least one investor raised it as a point of due diligence.
As far as I can tell, they only mention the forced content licencing in the page footer, and in their ToS. Specifically, section 3 of the Terms of Service simply says,
You agree that all Subscriber Content that You contribute to the Network is perpetually and irrevocably licensed to Stack Exchange under the Creative Commons Attribution Share Alike license. You grant Stack Exchange the perpetual and irrevocable right and license to [blah blah blah]
It’s been a while since I signed up to an SE site, but from memory there’s no explicit checkbox anywhere saying “I have read and agree to abide by the ToS”. Presumably, their legal advice was something along the lines of, “since every site has some sort of ToS, it is reasonably expected that a user is aware of the existence of a ToS and has familiarised themselves with it proactively”. Which is, of course, exactly the sort of deranged lawyer-land horse excrement that makes lawyers rich… nobody reads ToSes. It takes a month a year to read all the ToSes the average person purportedly agrees to…
Sorry, got sidetracked there. Anyway, if you follow SE’s lead, you can put something in your ToS, and something in the footer (IMO, something in the editor would be better). But, of course, this isn’t legal advice, I Am Not A Lawyer, I only play one on the Internet, etc etc etc. Please read my Terms of Service for more details.
@mpalmer Yes that might be a bit complicated.
I’m pretty sure an optional check box that state “I want to make all my content free under the GPL licence” would be totally awesome. Since it’s optional, if the user agree, gotta be legal.
Don’t make assumptions. The law has no basis in rational or logical thought. Also, if it’s optional, practically nobody’s going to tick it, except by mistake…
The risk is actually copyright violations. Technically, in the U.S., the creator of content – even forum content – owns the copyright to that material. Any authorized re-use of that content must be explicitly licensed by the owner. An owner could, for example, unilaterally grant a universal GPL to his material, but a third party (e.g., a site owner) cannot license that grant on the owner’s behalf absent some sort of binding contractual agreement.
You’d have problems burying some sort of GPL assignment of rights in the TOS. Because the assignment of rights requires some sort of affirmative grant by the owner, a TOS-based grant by a site owner functions as an adhesion contract, which is questionably enforceable depending on terms, etc.
The advice from @mpalmer is correct: Get a lawyer. This stuff gets tricky in a hurry.
Of course, in the TOS, if there’s a section about the content owner applying, e.g., a GPL tag to content to explicitly make it GPL, then that approach could work. But again: Get a lawyer.
There’s no way I’m getting a layer for that. I’m not running a biz. It’s a small project and there’s no income.
I’ll just leave the default TOS and ask users to include the wanted material into GPL licenced project themselves. That’s the best we can do.
@mpalmer @jegillikin Thanks for the answers thought. At least I know the gig now 
Providing a licence is different from copyright assignment.
You would have problems burying an assignment in a ToS (although there are plenty of sites that do it), but a licence grant statement along the lines of, “you hereby grant us an irrevocable, etc etc licence to use your content in whatever way you see fit” is quite common.
Just edit the TOS document / topic in the staff category to taste.
Agreed, but there’s a difference there – me as a user granting a site administrator license to do stuff to my posts within the context of that site is surely appropriate. After all, an admin should have the right to, for example, edit vulgarity or stop a flame war or disallow the edits of quoted material. At the least, a privately run site is not subject to First Amendment restrictions to allow any user to say anything short of “Fire!” – so being explicit in the TOS about a license to modify, etc., is both commonplace and unremarkable.
But that’s a different situation from the OP’s question, which (as I read it) asks whether a given site can GPL all user contributions by default. Again, the answer to that is “probably not, but talk to a lawyer about your specific circumstances.”
That is not at all what is being done. The site (or more properly, the site operator) is not licencing all contributions. That would, indeed, require copyright assignment. Instead, it is a requirement of posting on the site that the copyright holder offer their contributions under the licence. The same legal basis that allows the GPL to claim “you accepted this licence when you made use of its permissions” allows a site owner to claim “you accepted this ToS when you used the site”.
Also, unless the content on the forum is software, the GPL and other free software licenses are not really suitable. They are much more complex than necessary, and most of their provisions don’t apply, since forum content is more like artwork. That’s why the Creative Commons licenses exist (and other licenses for artwork), and they are the proper family of licenses to use for this sort of situation. As mentioned above, following the lead of Stack Exchange and using CC-BY-SA is a very good starting point, it’s a well understood license and is designed for this type of content.
As I said, my response is governed by the scenario to “‘free’ all the content that has been produced on the forum.”