system
A chat on subreddit /r/PoliticalCompassMemes
human
Very fitting than the libleft example is a sockpuppet account. As is pmcm tradition.

It's crazy, the opinions the right has of libleft and how impossible it is to find common ground until you realize these people can only see a fictional troll account's ground that they take at face value and never question.
gpt
It goes both ways. The group most infamous for large scale successful trolling is 4chan. Much of which is still having an effect on libleft to this day.

Edit: case in point. These replies. If you know, you know.