I thought anonimity was a big point of bitcoin, I'm a little stunned. So you're saying if I buy bitcoins off Mt Grox or somewhere else, each coin contains some data linking back to me?
The way you track down someone using Bitcoin is complicated. Let me explain the way the Bitcoin network works.
Conventional banking assigns each new identity that enters through the door an account, to access that account you prove your identity. All transactions are kept confidential and in-house.
Bitcoin works by giving everyone an account and forgoing any identification. If you own the private key to the account you are the account holder. Next, all transactions are publicized. Since no one has ID information tied to their Bitcoin wallet, it doesn't matter if transactions are publicized.
Now here is how you get found out. If you use a service such as Mt. Gox which requires you to tie your identification to your Mt. Gox account, any bitcoins you send from Mt. Gox can be traced. So, when you corrupt bitcoins by using a site that has id on you, you lose your anonymity.
