User blog comment:Meighan/Wiki Wisdom: Reacting to Trolls and Vandalism/@comment-33628828-20111110230752/@comment-33628828-20111111003351

The problem is that it is very hard to determine what is actually intentional vandalism. Even blanking a page can be an accident. On large wikis with lots of countervandals especially, giving a warning after just about any bad edit does very little harm - in the worst case scenario, they vandalize again and get blocked.