Hmm, I am pretty sure they can't find out your EXACT address from an IP, residential customers anyway. They would have to call your ISP and ask for it, which I doubt they would give away unless it was the police or the government.
and for one to steal your password, it can only be done by certain circumstances, like a certain virus on your computer that records the keys you have typed, (they can steal your Credit Card numbers, passwords etc.) but don't worry, not every single virus does that.
2nd circumstance is that you are on a fake website made to look like the real thing. For example, you click a link that takes you to a website that looks exactly like Myspace, you try to log in, you type in your name and pass, click submit. After you click submit, that information goes right to the hacker, which is why it's important to check the URL at the top. If it says anything other than myspace.com (myspace.ca, myspace.org etc.) then it's most likely fake.