just as a matter of interest, are the managers of various popular bitcoin websites willing to disclose their policies and practices on retaining logs related to bitcoin addresses? i recognise that statements from such people would be hard to confirm, but most of them appear honourable.
for example, theymos, how long do you retain the httpd logs for the block explorer, thus letting you tie bitcoin addresses to ip addresses (or to each other, depending on the queries you receive)?
gavin, do you keep records of which google accounts and ip addresses are tied to bitcoin addresses that receive payments from the faucet, or only that payments were made in response to requests that were received from particular accounts and ip addresses? (i know you need to do the latter to prevent abuse.)