I don't fully understand trolls. You can make a completely innocent comment on a YouTube video (nothing controversial and nothing disagreeable), but some people have a problem with what you said. For example, I make an innocent comment about my favorite part of a video on YouTube and someone angrily says "who cares what you think, or nobody asked you." I am not even talking to them, I am talking to the person who created the video. Then they attack other users who make innocent comments. One commenter would say, "that was funny." Then the troll would say very angrily, "that was not funny you idiot!" When the video was a comedy and supposed to be funny. Then they try to start a fight with you.
What are they looking for? Why do they attack innocent commenters that are innocently commenting and not trying to start a fight?