I still have yet to see an analysis that picks a random address from the blockchain and successfully identifies its owner by name.
All coins will probably be "tainted" at some stage ......even if you could say a coin was involved in an illegal transaction once ,god knows how many tumblers and wallets and banks and gambling sites its going to be in after that
the only possible danger would maybe be in immediate reciept of a marked coin (like set up by the cops in a sting doing something illegal etc )
i dont think its worth worrying about tbh
