I haven't tried to prove or disprove this statement, but it could easily be selection bias. If you're in a bubble, you're going to be very aware of violence done to people you sympathize with, and less aware of violence done to people you don't.
The protests that aren't oppressed are the ones that are utterly ineffective. Think flash in the pan pussy hat protests, that are more about making the participants feel good about themselves than actually forcing change.
If a protest has the capability to last and continue bringing their issue to the forefront it will be met with oppression.
Probably accurate. Anything that upsets the status quo, costs business owners money, or otherwise threatens reelection chances is going to be met with force. Or, more likely, a smear campaign, ridicule, and then force