I wonder if they give them a little course on how to bash successfully (like accusing people of being "hysterical" ), or if they just hire sociopaths who are naturally good at it?

Reminder: yesterday someconcerns posted several links to articles about Monsanto hiring trolls to shout down opposition to their chemicals. It is NOT an urban myth that there are hired posters who pump or bash as their employer asks.

There's another word for those people: scum.