I've been approached by a group that want me to build a website of questionable legality. Can I as the developer get in trouble? Or will the people who asked me to develop it get in trouble?
Edit: basically it's a site where people might be upset that they are on the site... and could sue. All content would be user generated though.
It depends on what exactly your role is. If you're a web designer and they give you the content, then they'll be the ones who are in trouble.
If you're writing software to, say, steal people's internet banking passwords, then yes, you're probably in trouble then.
IANAL.
(I've always wanted to say that)
Get a proper legal advice from a professional lawyer.
We neither know enough about the situation (we even don't know in which country you live), nor are qualified enough to give a reliable answer.
My gut feeling is: if you aren't comfortable with the job, then don't take it.
NOTE: I am not a lawyer, and the following is not legal advice. This is just my understanding of how things are. Serious legal questions should be taken to a lawyer.
In the U.S>, the normal legal tests are 1) Did you know it was illegal? and 2) Should you have known? (2) is to eliminate people "playing dumb" as a defense. Note that it also means that "being dumb" is no defense either.
So what if you do know it's illegal (or should have know)? Well, if you participate in it in any way, then under the law, you could be just as guilty as they are (how much varies by state). Further, if you do not participate in the illegal enterprise, but also do not report it (i.e., just look the other way), you could still be found culpable under the law.
If I was in the situation that you describe I would consult a lawyer. Immediately. And I strongly advise you to do the same. This is by far the smartest thing that you can do.
In web development you should always assume that someone somewhere can expose you as the one that created the website, so be careful with that.
If it came down to lawsuits, then they just go after whoever has the most money first, then down the food chain.
These days even the president can't rely on legal advice without being threatened with a lawsuit. But assuming for a second that they won't or can't come after you, do you need the work enough to compromise your own integrity?
IMHO it depends on the contract you sign..
I'm following the rule - If I make a gun, I'm not responsible if someone shoots someone else with that gun. I just made the gun and fullfilled the contract and am not responsible for usage of the product.
But I might be wrong - I'm not a lawyer at all ;-)