Threadbear
A person who comments on a thread dedicated to a topic they pretend to abhor but secretly find fascinating, if for no other reason than they are compelled to act out a deep-seated impulse to be a total opinionated douche bag. This condition is often coupled with bitchitus and in some people can lead to chronic dickiness.
If one encounters a threadbear squatting on a site, it is best to let it shit then move on without interruption.