It is a poorly understood term people use to shoot down unpopular opinion. This is so common. Here is one from last day where a user is accused of being a troll for criticizing the new StarWars trailer.

http://www.reddit.com/r/movies/comments/32yudu/furious_7_cro...

Another example is my experience from /r/php. If you go there and criticize the language, you will be called a troll and will be eventually labeled as such. People are emotional, and they will use terms like this when their beliefs are threatened. It is an easy response. In a while, everything you say will be, by default, down voted and even lead to a ban solely out of this impression.