I've been wondering this since the '90s, with the crypto and copyright craziness. At least crypto is pretty much legal now. On the other hand, IIRC, a number of info-security conferences have moved out of the US since the copyright lobby has made their fields of study dangerous to pursue in the US.

On the bright side, wossname, Steve Kurtz, did eventually get his charges thrown out, after a few years of persecution.