We already have the Fellowship of the Sun but this is something new.... My guess is this is gonna be something that the vamps, especially, Nan and/or Bill, are gonna have to fight against it.
They even have a website http://vamps-kill.squarespace.com/ with this text in the main page:
Wake up people before we are all DEAD. Vampires are EVIL KILLERS who feed off of humans and they are EATING US ALIVE. This site is dedicated to proving that bloodsuckers ARE AMONG US and that we must stop at nothing to rid America of these scavengers.
This is something that we are probably gonna see in the next episodes, IMO!!
here are some of the vids