I agree that moderating trolls and limited return-trolls is important.

I cannot say I'm sure that [this kind of defacing](https://english.stackexchange.com/q/125723/23834) benefits the site more than it punishes the troll. I think it just looks weird to the irregular user, whom doesn't know that such a person is trolling. 

Should we use the 'protected' status to lock-down a question and prevent trolls from downvoting people, etc.?