Anything adding an extra layer of complexity is a massive NO-GO for bitcoin IMO.
You have to take into account that there are hundreds of ways such a system would be gamed. A complexity arms race is the least thing bitcoin needs.
+1
As soon as there's such a mechanism, stolen coins will find a way to avoid being detected, there's just no way you can do that 100% reliably. This would only result in a great big mess - people wrongfully accusing others of having their coins stolen (even if it was a regular payment or donation) just to get them into trouble, people fighting over evidence and reputation, online wallet services getting into trouble because some think their acceptance policies are not strict enough, tainting coins of innocent others in the process, people flooding donation addresses with tainted coins,...
Also, what would be the next step? Refuse blocks from "shady" miners who include transactions with tainted fees?
We really don't need that - fighting Bitcoin thefts at that level is just not the way to go. You'd only make it a bit harder for Bitcoin thieves at the cost of making Bitcoin a much more miserable experience for everyone else!
Oh and I'm not trying to talk anybody out of implementing such a system, please go ahead and do it, just don't expect it to become widely adopted. Even people thinking such a system would be a good idea in principle are likely to disagree on the details, fighting and lobbying for their favored policies, etc... In the end, it would have been much more effective to just make two-factor authentication easy to use for everyone.