I've seen countless posts about the tankie problem here in the lemmyverse
I'm not sure I've seen any evidence of it existing though, is it just a Boogeyman, or so something that happened a while back? An in joke of some sort?
Some instances such as Hexbear federate for the sole purpose of brigading to harass and argue in bad faith. Have you not been paying attention to the countless threads they have been spamming?
Take a look on any post outside of lemmy.world that remotely mentions China, Russia, Ukraine or North Korea, and you'll see exactly what I'm talking about. Unless their mass flooding of pig poop emojis, bad faith arguments and authoritarian apologetics don't count as trolling or brigading to shut down discussion.