Ed Felten has some thoughts on California's proposed version of the INDUCE act, which fortunately didn't make it through Congress last year.
"The main change from the previous version of the bill is the requirement to include filtering technologies; the previous version had required instead that the person "take reasonable care in preventing" bad uses of the software. This part of the bill is odd in several ways.
First, if the system in question uses a client-server architecture (as in the original Napster system), the bill applies only to the client-side software, since only the client software meets the bill's definition of P2P. Since the bill requires that a filter be incorporated into the P2P software, a provider could not protect itself by doing server-side filtering, even if that filtering were perfectly effective. This bill doesn't just mandate filtering, it mandates client-side filtering."