Have a MAC and use Vuze to download old movies without any trouble. I stay away from the new releases and buy them if I like them. Like Role Models for example.
Some older movies I didn't have but wanted to watch as an .AVI was Rounders and Boondock Saints. Great flicks.
I stay away from all new music releases. Just buy it if you like it. $10 for an album of an artist you really like is worth it imho. If you want something oldschool and you don't know of anyone who has the .mp3's THEN YOU NEED MORE GEEK FRIENDS.
With most torrents....get on the thing, get what you need, log off and don't seed. Otherwise, its always going to be somewhat of a risk to download anything as anyone can see your IP address, even with a fancy firewall and cloaking software.