BitTorrent is not really a file sharing program, like for example eMule, Kazaa, etc.
It's more a file transfer protocol (like FTP, or even HTML in some sense) that just happens to leverage on a file swarming / P2P tech to delivers files with great efficiency, even with "small pipes".
For example, it enable a small developer to deliver his last ZIP package to a giant audiences even from his small home server.
Since you (the BitTorrent client user) have to click on a .torrent link to begin the download, there's not really much more risks involved than downloading from any others "usual" HTTP/FTP links.
You may want to give a look to the BitTorrent home
for a better explanation than mine!
Sorry, I know my English is terrible. I hope to be understandable! I'm also glad that there's a Spell Check button on this forum!