Wikipedia:You may need to feed the trolls

Any user who deliberately attempts to damage Wikipedia is a vandal. A vandal who intentionally makes non-constructive edits with the goal of provoking an angry reaction from other users is a troll. It is generally best to deny recognition to all such ill-intentioned individuals. It can be difficult to determine, though, whether a particular non-constructive edit is deliberate, or whether a deliberately non-constructive edit is intended to provoke anger. Many edits that appear to be inappropriate are actually well-intended. Some apparent trolls are actually inappropriate attempts to prove a point or to challenge Wikipedia policy.

Unless there is clear evidence that a particular user or a particular edit is ill-intended, however, Wikipedia users are expected to assume good faith. Given the difficulty in determining intention, it is necessary to engage with other editors over points of dispute and to reach a consensus. Unfortunately, this sometimes means giving ill-intentioned editors the attention that they seek.

In short, sometimes you must feed the trolls until you can ascertain their intentions.