Sure you can, but there are two points worth mentioning. The network could and should be built to adapt to such potential attacks. Spamming transactions (essen

Sure you can, but there are two points worth mentioning. The network could and should be built to adapt to such potential attacks. Spamming transactions (essentially a ddos attack) should be banned anyway. Accidental receipt of stolen goods isn't a crime if you immediately turn them over to the police. People could forward all those coins over to a law enforcement account and receive no penalties while the sender would lose money without gaining anything. This too could be automated.