On: The cyclist behind an anti-cyclist Facebook group

[js2]

That's a variation of Poe's law:

"Without a winking smiley or other blatant display of humor, it is utterly impossible to parody a Creationist in such a way that someone won't mistake for the genuine article."

https://en.wikipedia.org/wiki/Poe%27s_law

[seren → js2]

It is a corollary but it is an application to people in large numbers.

Since, in the long term, there is always less people in on the joke than new followers, you are guaranteed that the community is going to be taken over in the end.