The CDA was later struck down by the supreme court, thanks to a challenge by the ACLU: http://epic.org/free_speech/cda/
http://en.wikipedia.org/wiki/Section_230_of_the_Communicatio...
If SOPA passes, I hold out very little hope that this Supreme Court will do much of anything to ameliorate it .
Probably won't work legally, but it's worth a thought...