http://www.cnn.com/2001/LAW/10/30/sc....ap/index.html
Rmember that ridiculous clause of that Clinton bill about the Internet Decency Act? It said something like that you couldn't suggest people under 18 were having sex cause that counted as child porn (making it illegal to rent countless Hollywood movies, from Fast Times to Porkys to Wild Things to recently Traffic though that hasn't actually been enforced).
Well the Supreme Court is looking at it now; in a case brilliantly labelled Ashcroft vs. Free Speech Coalition.
The frightening part of the law was that it used words like "conveys the impression" and "appears to be" when making a decision about whether artists shall be labelled child pornographers in the eyes of the law and mainstream media.
Anyway, interesting stuff since child porn is certainly the way they are gonna go after p2p in the end, especially in cases like Freenet where people have content and helping searches they are not aware of.