I just spent a while doing this in Varrock. Afer the first couple I went to bank, cleared my inventory and put on an earth tiara. After each autoer got killed I picked up 27 of his load and ran up to earth them. Maybe Jagex could add a couple more muggers to the area. It seems quite effective. Maybe Jagex could add some kind of NPC Mod in areas frequented by autoers. All it would need to do is Flash the crown occasioanlly. Maybe it could be in the form of a town crier, or a mad, mumbling hermit. Anything which could make occasional public conversation in context.