If I get your meaning Zarak, that's actually from the same etymological roots as the fisherman's "troll". Originally it was to stroll around aimlessly, and very similar to "trawl" which is to use some sort of dragnet, as well as to "trail" or drag something behind. "Trolling" in the fishing sense then can be readily understood as wandering somewhat aimlessly like strolling, but in a boat with a baited line cast out. So then, the slang meaning I think you're implying is drawn from that, being to roam around with the "baited hook" of sorts being one's self, and it not being fish one is trying to catch.
The etymology of the mythical "troll" (only used as a noun) is quite different and unrelated to this sense of "troll" (which is really only officially a verb.) The verb form has been sort of coloquially combined with the mythical noun form to produce a new noun, indicative of a foul individual who puts out bait and waits for people to snap it up.
I don't think you will find a noun form of "troll" in any dictionary that is listed as "one who trolls" or something to that effect.
