Well, if you don't trust yourself barborrico, who can you trust ;-)

Honnest witnesses are here to warranty the chain integrity as lighthouses/milestones. And as I stated to pineapple express, bad behaviors can be detected by honnest witnesses. For instance, if dishonnest witnesses collude in an attempt to rewrite history, this foolish act will inevitabily generate orphan units and that breaks the chain integrity of these units until the genesis unit. Honnest witnesses will then select a parallel history to keep chain integrity.