Anonymous was by definition an Anonymous poster on an image board. In its early form as anything resembling vaguely a "group" that does things (it wasn't a "group" quite) there were raids/trolls against targets for the lulz. A pure and simple time. Later, a touch of morality came into play, and Anon used their skills to attack those who deserved it rather than simply those yielding the most lulz, leading us to the campaign against the Church of Scientology. After this, Anon was more and more oriented toward some attitude of just revenge or sometimes destructively discouraging a behavior, instead of just fucking with people. "Moralfags" and "Moralfaggotry" were the words of the day.

Because Anon is not really one well-defined group from one place, there never will be any good consistency in what it looks like Anon as a whole stands for.

4chan certainly did not "create the existence of the net troll", which somehow this writer is supposing to be exclusive to the idea of Anonymous, but when they say it spawned social justice movements, they might mean the involvement of moot and 4chan in GamerGate and the social justice movement, by no means a "spawning" (of the movement -- though maybe, in part, they spawned GamerGate) but significant in that it apparently led to the thrashing death of 4chan. If by spawning social justice movements they mean raids/attacks "for justice", then sure, but the Social Justice movement isn't one of the things Anon was really anywhere near agreed about. I never really got into the whole thing (I was busy on 7chan, TOTSE, SA) but these should tell you enough, albeit with some bias:

https://encyclopediadramatica.se/GamerGate#m00t.27s_GamerGate_Sellout

https://encyclopediadramatica.se/4chan#4chan_is_kill

https://encyclopediadramatica.se/4chan#January_2015_-_Final_sellout_and_le_cuck_est_mort

https://encyclopediadramatica.se/4chan#September_2015_-_The_End_Two_-_Electric_Boogaloo