That's an excellent description of them. I'd never heard it before.
I just made it up, because we you see that some individuals post 10 to 20 negative articles a day, you suspect that they must enjoy riling folks up for the number of clicks they can get. That is not much different than a vampire trying to suck the last drop of blood (hope) out of folks that are inundated with bad news. If we try just a little bit, we can find a lot of good to be thankful for.