I don't use any of these sites...everyone here already knows how much I rag on kazaa, and all the rest....you've all seen me say "I don't share files, I send them"
that said, if a legitimate tool is used by some illegitimately, nothing we should do about that.
so long as there's a legitimate purpose for any service, then it's up to each individual to his own conscience.
obvious example...anyone here think we should ban hunting knives?
I didn't think so
on the other hand, if a weapon was marketed as a tool for murder, then of course you'd restrict access.
same thing for these sites...if the marketing and design is legitimate...it's use is conciencious