Trolling means something different these days. It used to mean circulating and moving around, often in a fishing context. That sense of movement may still resonate, but trolling has now become the occupation of trolls. Take these definitions from a popular forum's rules:
Trolls are people who for no reason want to disrupt a forum topic by constantly posting out of context posts, derogatory comments, throwing insults, making personal attacks and deliberately inciting a negative response from other members. This is called trolling in public forums and won't be tolerated here.
Fair enough. What site administrator wouldn't want to curtail such negative behaviour? But let's look at that rule again:
Trolls are people who for no reason want to...
This is of course a nonsense. How can a writer be construed as lacking in reason, especially one actively attempting to incite a negative response (the key word being action)? Unreasonable comments may abound, but I've yet to find a reasonless writer.