That's several questions. The first question is an obvious yes. Look at Facebook pages like 'occupy democrats.' The page and website of the same name seem to exist purely to keep people as angry as possible.
There are lots more pages and websites also doing the same thing, and of course some are on the opposite side of the issues.
Is this working for us? Who is us? I think those inflammatory, and often very non-factual hyper partisan sites are getting what the site owners want out of it all. If they could be held liable in criminal cases for crimes they inspire...that would be a slippery slope, but there could be something to such a hypothetical bad event.
It's a nightmare.
The extreme left wing sites are pushing covetousness, a material possession sort of envy. Communist have a very violent history. So I'm pretty concerned about it all.
Gosh, I wish I had a good answer for how we should deal with envy and grievance. See, envy is a negative emotion. Everyone deals with it. But when you say 'grievance,' I think the term implies that someone was definitely wronged. Well, I checked the big G search engine. They say a grievance can be an imagined wrong one has sustained.
People aren't being very adult about it all when they think they've a grievance because they didn't get the POTUS they wanted, or they don't make the wages they believe they deserve.