I've done some work on this (http://arxiv.org/abs/1107.4524 http://arxiv.org/abs/1107.4524) and the phenomenon that coderr describes is very widespread in pract

I've done some work on this (http://arxiv.org/abs/1107.4524 http://arxiv.org/abs/1107.4524) and the phenomenon that coderr describes is very widespread in practice (we can examine this passively, from the transaction history) and its linking identities we can be pretty sure the users didn't intend to have linked. I'd say that anyone concerned about anonymity should be using a client with the functionality that coderr's patch provides, and be incredibly careful using Bitcoin in general.