When the G-Whatever came here to Pittsburgh, during the Obama Regime, Downtown was surrounded by a chain link fence.It was very disturbing. We had riots in the City, though outside the fence.
G-20 came here. Here is a compilation of G-20 scenes from 2009 in Pittsburgh. I recall they used the noise cannon, among other things. https://youtu.be/W-cxHC_JU8o
The “riots” were a couple dozen people protected by the national guard. Mike Pintek interviewed a reporter (international credentials) who embedded herself in the “protest”. I came away from that realizing all the “security” was about making sure the residents gave up their rights without a fuss. It was for their safety ya know.