The very obvious clues are those pallets of bricks appearing out of nowhere. Take note too that nobody works for free. Even when President Donald Trump was holding huge rallies, way before Corona Virus, you had violent thugs assaulting Trump supporters coming out of the venue after the rallies. Those thugs were being paid like $1600 for a couple of hours of riots and public destruction of property. Some thugs have molotov cocktails and obviously, prepared for this.
No, this was not just a spontaneous demonstrations. It is orchestrated. Even those confronting the police like the 75 year old extreme liberal who blocked police, was saying something to the police to their faces. That was before he was pushed. He lost his balance but, he brought it on himself. Probably, a paid agitator himself. Note, he was the only one and what the hell was he doing in a police assembly point?