Why are these guys masked? Liberals and many Conservatives were shocked at the militarization of police, and the the way they attacked demonstrators, the press and both local and international camera crews in Ferguson, Missouri. In my opinion, the Ferguson police were either a gang out of control or, more likely operating under bad orders from their superiors.
Now we hear reports of Chicago police using CIA-like black site tactics at their Homan Square facility, holding people incognito without access to a lawyer or even without being booked and put into the system for 17 - 24 hours. So Liberals, do you really expect us to turn in our guns and trust these guys? Seriously? I don't think so.
With that said, most cops, like 99.8% of them are decent men and women doing a dangerous job to the best of their ability. But even good cops can be given bad orders or bad training. My point here is that any part of the government can become corrupt and an armed citizenry is a powerful check on that.