From the FAQ:
Our artistic intent is to cause people to realize and think about just how subconsciously willing they are to suspend belief. If I get a tweet from a celebrity addressed to me, referring to something that only my friends know, do I immediately realize that it’s a joke, or do I even for a minute actually think that this celebrity is actually tweeting me? If I do, does that say something about me or does it say something about the world in which we all live? We are using Twitter “tweets” as an example of the kind of Internet communication that people tend to accept as fact, but the cultural phenomenon on which we are commenting could just as easily happen with Wikipedia, Facebook, or any other site on which people rely for information.
Deep! TweetForger is maybe a little too polite for mischief’s sake about highlighting the degree to which a Tweet isn’t real — the fake Tweet template proclaims the fakeness of the thing several times, and there’s even a giant box that eventually pops up that says “This is a FORGED tweet!” — and the tweetforger URL may be the biggest tell of all. (TweetForger plus a URL shortener which doesn’t auto-redirect could be more promising.) But that’s probably all for the better, and it does look pretty. Check er out here.
Have a tip we should know? firstname.lastname@example.org