It has absolutely nothing to do with any kind of police culture, the police are reacting to what seems to be an extremely dangerous situation that anyone with a sense of self-preservation would want to be heavily armed to deal with. This is a symptom of how the anonymity provided by the internet leads many weak minded people to a disconnection with natural senses of responsibility, resulting in behavior that resembles that of a sociopath.

The same thing happens with little kids before they develop good problem solving or socialization skills. Little Timmy wants attention so instead of doing something reasonable, like talking to someone or offering to play a game, he just walks up and punches them in the arm. Then when people inevitably start to ignore being punched in the arm, he progresses to throwing rocks at them. Then when they stop reacting to that, I guess he calls the police and gets SWAT to raid their house and potentially destroy their lives. That's all internet trolls are; just taller, fatter children with a lot more resources available to them. Honestly I think it should be a felony and the person should have their internet activity monitored for the rest of their life.

EDIT: just wanted to add that I do think we have some big problems in our police culture, just that this isn't a symptom of them.