My friend, who is the security-minded administrator of a somewhat huge public XMPP server, told me that he always disables Autofill/AutoType. He uses KeepAssXC

My friend, who is the security-minded administrator of a somewhat huge public XMPP server, told me that he always disables Autofill/AutoType. He uses KeepAssXC and manually copy-pastes his details into forms. Said that he doesn't trust autofilling because of JavaScript exploits which would compromise his passwords. I don't recall if he mentioned it or not, but I'm pretty sure he also uses some utility that wipes his clipboard every so often (if KeepAssXC doesn't do that automatically)