Fedora unboxing.

Quick answer:

The Sovereign Citizen believes in a "straw man", a legal entity which is fabricated by the government to prop economic systems. By signing a Social Security card, your "straw man" is created. By using absurd/schizophrenic legal voodoo, you can leverage against your straw man's manufacturer's suggested retail price and reap the rewards.

Of course, the exact legalese required to unlock your straw man's value has yet to be discovered, and so trial and error must be utilized like velociraptors against the electric fence of Jurassic Park. This is the central theoretical conceit of the Sovereign Citizen.

They've got a child's view of the Social Contract: since they didn't explicitly agree to the terms and conditions of living in the US, they feel they aren't bound by the law as you and I know it. So yeah, they've fanfictioned all manner of other laws that are somehow binding in ways that normal laws aren't.

Dude doesn't mind recognizing legal tender issued by the Department of the Treasury, though.

Am I a terrible person for wishing a little police brutality on sovereign citizens? I suppose I don't mind being terrible in this particular circumstance.

You are far from a terrible person. You're normal. These fuckers a kamikazes destroying our country.

They're poor people who act like they're billionaires who demand the same lack of authority the rich have.

Sovereign Citizens aren't really REAL AMERICANS (tm) anyways.

No, like, literally they aren't.

It's important to note here that NO ONE has ever succeeded in using any sort of "freeman on the land" tactics successfully anywhere in the world (and yes, this happens in other countries, most notably Canada and the UK believe it or not). Most people who have made a good chunk of money off of selling books and videos about this shit have famously never used any of these legal tactics themselves and there are dozens of cases where people using this shit in a real legal situation have either failed miserably or pissed off the courts enough to make things even worse.
Even Alex Jones, of all fucking people, has been trying to talk most of his nutbag fans out of using this shit.

I've never seen one. If you find one you submit that shit.

Er, one could argue that the Moorish Science Temple was doing this in the 1920s.

I think it's less about the potential beatings and more about the fact that SCs are the whitest motherfuckers ever.

The Sovereign Citizen movement actually started among white nationalists, but it has recently started gaining with crazy black people too. There was a group in Georgia who tried to steal houses with Sovereign Citizen tactics, a group who tried to defend themselves from murder and the death penalty with it, and most famously Wesley Snipes tried to stop paying taxes and have his strawman be on the hook for it instead, resulting in 3 years in prison. Most black people who do this do actually claim some connection to the Moorish Science Temple.

That's about where I gave up too

This guy can't even convince a video camera. I'm sure the cop will be impressed.

Certainly, if by surprise you mean "confirm my fears and send me into a spiral of absolute depression".