> When you purchase something via bitcoins, it is public information. You have an address that is public that says abcdef bought this. abcdef cant be traced back to anyone unless you publicly announce you are abcdef.

Definitely not. Transactions are public, but definitely not the information that connects transactions to identities or merchants.

> When you buy a pizza, you are saying abcdef lives at this address. So anyone with a subpoena on Dominos records can tie your address to your previous purchases.

Also wrong. If you send the transaction from a web wallet, the merchant receiving the coins can hardly say anything about you.

It seems that there are lots of trolls here shouting something about bitcoin which they don't really know much about.