This is my thought process: there is no higher up that has created language and said "it is thus so". Language evolved when our brain restructured itself 200 thousand (or was it 100 thousand?) years ago, which allowed us to produce and understand language. Ever since then, language has evolved, and is also currently evolving, with new words entering the English language constantly. However, what words are officially part of the English language, and which are jargon? The way a language officially enters the English lagnuage is when it is recognized by a major dictionary publisher, such as Oxford or Webster (words such as "google" have recently been recognized like this).
decebal, I would be interested to hear in more detail where your interpretation on the use of 'troll' differs, as I am aware that to an extent claiming 'misuse' depends on my own experience.
Pulling out an old copy of Webster's Encyclopedic Dictionary that I have lying around from 1988 (therefore it may be outdated), the definition of "troll" is as follows:
troll: 1. v.t. to sing (a song) in a loud, jolly, carefree way || to fish in (a lake, etc.) or to fish for, by drawing a line with a spoon attached behind a boat. || v.i. to fish in this way || to sing away loudly and merrily || 2. n. the act of trolling || the spoon or spoon and line used in trolling || (Br.) the reel of a fishing rod [etym. doubtful]
troll: n. (Scand. mythol.) one of the supernatural beings, formerly thought of as giants, but later as dwarves, inhabiting caves, hills etc. [O.N.]
Your definition of troll is not included in the above definition, nor is it in any other recognized dictionary. However, there is some merit towards the idea that your definition is correct, as the users of the language define it. That being said, because the users of the language, such as you and me, define the language in ways that are not recognized by official entities, you cannot discount the way someone uses a word, when you are not using an official definition of said word, either.
tl;dr: Language is defined by who uses it, which means that dictionaries can be wrong because they don't include jargon, Crocefisso may be wrong because he is not using an official definition, and the "misusers" of the word "troll" may also be wrong because of the same reason. It all depends.