Watch out! A US judge ordered Google to give up viewer information- the usernames and IP addresses for people who watched every single video ever posted on YouTube since it began. Looks like this might break a privacy law put in place a loooong time ago that makes peoples video rental habits private (after some senator's porno-renting habits were published in a paper).
I skimmed to Canadian Privacy Act to find out what we'd have to say about all this, and while I got bored before I got to anything relevant, I did find that there is an interested clause in the "knowledge and consent" section. Basically, you need someone's knowledge and consent to access their personal information unless you're investigating their crime and they'll destroy it before you get there or other such legal/emergency situations. OR you can access personal information without knowlege or consent if you're using it for journalistic, artistic, or literary purposes. I may be misunderstanding this, but it sounds to me like in Canada it's illegal to access someone's personal information without their consent, unless you're going to publish it in a paper or use it in art (that will, theoretically, be viewed publicly). Awesome.