Saying file sharing is illegal is a bad statement. It depends on what you are sharing.
This site does not allow for discussion of exchanging other peoples property where you do not have permission. I think it would be fine to discuss using P2P networks for exchanging open source or freeware media. Things that the original distributor intended to have freely shareable.
At the top of each forum you'll see "Announcement: Forum Rules". Read that. See rule 4.