Right now the US is basically a two-party system with both parties bribbed by the same health insurance companies. The will of the people demands change, yet both parties refuse to implement change.
Withholding your vote does nothing as it's essentially a two-party system. Voting for one party or the other does nothing as they're both paid off by the same health insurance companies.
In desperate times when the government no longer represents the people, people turn to vigilantism to solve ongoing problems, as we saw with the killing of the CEO.
It's going to get a lot worse, there WILL be more killings.