Tankies. I argue with them constantly.

My opinion, they're mostly middle class westerners that grew up in a cradle of empire, sucking from the teat of exploitative resource extraction. Then when they stopped seeing the benefits of imperialism as their country fell into late stage capitalism and eating itself alive, they turn their resentment against capitalism and correctly identify it as what's ailing their society, but somehow completely fall for the propaganda that there are socialist countries on this planet that are "fighting capitalism." They do nothing to challenge their deeply rooted western arrogance or imperialist savior complex, and begin lecturing people from smaller nations that actually, it's not imperialism when a country with a red flag does it.