lol, yes I can see now that we would essentially need to have a 1984 scenario play out in order to track something like this in an absolute fashion. Although if the promise of quantum computing pays off at least some of the things you mentioned would be possible. I didn't know that services like bitmixer existed- that pretty much nullifies bitcoin address tracking right there... I guess the thieves win in these instances.

Although- what if all bitcoin mixing services agreed to not accept coins from known illegal sources? Bear with me here... But what if an organization were founded that did nothing but track coins that were stolen in a way similar to what I suggested previously (watching the coins as they go from address to address ala "stolen gnome" style). Then, exchanges like bitmixer could cross check any incoming bitcoin mixing requests they get against the addresses provided by the organization? So there would be some sort of paper trail. Granted- ALL bitcoin exchanges would need to be doing this in order for it to be effective. But if they all did it it would actually benefit everyone because the general public would feel more confident using bitcoin as a currency and thus the overall value and use of bitcoin would increase.

Or would doing something like this invalidate some crucial part of what makes bitcoin relevant in the first place?