I'm very late to the party but I'm going to give my two cents anyway.

File sharing sites (MU/RS): cost money
Usenet/newsgroups: cost money to get older files
Torrents: FREE (always)

With Megaupload down, I can only assume that similar sites will be on their way out soon.

Newsgroups are nice when I stumble upon a gem from time to time, but most of the time I'm just paying every month and not really getting my money's worth.

Private torrent trackers are pretty damn safe (and no, demonoid is not a private tracker). I can't think of any private torrent sites that have been taken down since Oink and when Oink went down the only guy who got in trouble was the owner, who was arrested and then immediately released (after the UK news media got their story).

The thing is that the second private torrent sites get taken down, they will be up in a matter of days. All it takes is changing the domain and finding a country that will host the site without the worry of being taken down (and there are plenty of those countries).

Of the private torrent trackers that are around, MYSPLEEN is probably the safest for users. We don't keep members' email, IP, nothing. Myspleen also doesn't have a lot of stuff that is commercially available. Many content owners have even uploaded their material on myspleen and when we are asked to take stuff down, we do. For example we had a bootleg of The Book of Mormon musical and when we heard from their lawyer we took it down.