1. Do yourselves a favor and pe-emptively block PG’s communities. He’ll just delete anything you say counter to his “Vaguely Left-Wing” point of view, and he’ll perhaps ban you. He curates them to be ideological bubbles.
2. I and other mods & admins do ban people for vote spamming. For instance: 1) in the case of alt accounts that some people use solely for voting multiple times, 2) in the case of people who always downvote specific communities and 3) in the case of people who downvote a particular person regardless of the content.

Edit to add: He posts almost exclusively to the communities he mods.