[teataster]

It's not uncommon where I am from for plain clothes police to start riots. That delegitemizes the protestors and legitemizes violent action by the state. Pretty anti-liberal (classical sense :)

That's not exactly an undirected mob, but police and edgy teens seem to have an aligned interest.

[thinkingemote]

Additionally in the UK, the police often infiltrates protest organisations. They are often near the very top. The official line is that they cannot use entrapment but they are encouraged to help out and assist activists.

Any activist movement should consider themselves hacked and should look at.amd around the leadership for the site of the vulnerability.