I would wager that half of all social media now consists of 'bots. This is in addition to trading bots that control news cycles and stock markets.
If you've ever been swarmed after posting a controversial opinion, it has probably been a response by a team of 'bots. Been in FB or Twitter jail? It was probably a 'bot that complained about your post.
All the more reason to not feed the trolls.
One of my favourite responses to tolls: "Hello, 50-cent troll from China."