There's no law against paying intimidating people to stand in a particular place. That's what clubs do with bouncers.
And they have no more authority to use violence than any other citizen.
Also the obvious thing to do is offer your services for free to judges and prosecutors. The dark cyberpunk future is on its way and inevitable barring a total collapse.
I was walking in Las Vegas and private security started following me in a vehicle. I ignored them and kept walking. They followed me for several blocks, driving very slowly right behind, and occasionally severing at me. I recorded them and called 911. The police showed up right away. The police had a long chat with the private security about public spaces and intimidation.