Although I have bit torrent, I rarely use it.
If you are wanting to use it for downloading anything not entirely legal, bittorrent has the disadvantage in that it works on sharing principles, ie you have to contribute (upload) as well as download.....and if you look at the cases where people have been prosecuted, I doubt you will find anyone ever prosecuted for just downloading something.....its uploading/sharing that is bad in the eyes of the authorities.
I personaly don't use bittorrent as it often isnt quick enough for me as it relies on others sharing bandwidth, meaning it often slows down near the end of files, and rarely goes at your connections capability.
I stick with usenet...full speed constant 240k/sec on my 2mbit connection, and anything new gets posted on usenet before the torrent-boys get hold of it. And, you never have to upload or share anything.
The downside of usenet is, if you dont get it free from your ISP (rare these days), it costs about $15 a month.