bittyweb:  Bitcoin is only truly "anonymous" so long as you don't do anything with it.

In addition to what DannyHamilton said, suppose you buy bitcoins from your localbitcoins dealer.  Now imagine the Florida scenario where those bitcoin dealers were busted.  Now their records/wallets (and timestamps) are presumably in the hands of law enforcement.  The dealer may have been under surveillance when he sold to you.  You might be on the starbucks security camera where you met the dealer.  Maybe you bought a coffee at the starbucks with a credit card or are known to the staff.  etc etc.  Once "they" find some of your addresses and put some effort into taint analysis, things get interesting.

In reality, Bitcoin only gives you a degree of anonymity.  It gets you out of the scope of the NSA casually fishing through bank records to find likely names/addresses of people, but if somebody REALLY wants to find you, sooner or later, they will.  The more you interact with or trade with people, the more traces you leave.

In short, don't depend on bitcoin to keep you out of jail if you're breaking the law.  It isn't designed for that.  It is meant to keep you out of reach of "fishing expeditions", not a concerted law enforcement effort.