For those who want the bottom line up front, this is a staged event. I'll present my reasoning in the thread, but three, or more of these knuckleheads are actors.
There are several indicators
Environment
Conduct of the operation
Weapon discipline
Equipment https://twitter.com/bttr_as1/status/1284122403061338112

Environment
The street is completely empty. There are 9 people in this tableau
Driver
Goon 1
Goon 2
Protester 1
3 witnesses down the side street
Camera woman
Subject
1 passing car

NO OTHER PEOPLE. If this happened after a protest there would be a ton more people in the area.

Operation
1. There is no security for the Goons. They don't even attempt to provide their own security
2. They pass within arms reach of the Camera twice
3. They don't acknowledge Protester 1 when he gets too close to them
4. They don't watch their 6 when moving back to the van

There is no pat down
There is no cuffing (despite the props swinging from Goon 2's belt
The subject is loosely held and barely controlled as they approach the van
The Subject is allowed to enter the van first, unrestrained

The lack of security is the biggest tell. Protester 1 passes within arms reach during the "cuffing," yet Goon 1 doesn't acknowledge him. Instead there is a pause as both goons look left and right before leading the Subject away

Weapons
The Goons only have hand guns.
Goon 1 has never carried a firearm IRL. His hand hovers around the pistol, but he never grips it, NEVER

His hand is NEVER in a position to draw it. Nor is his hand ever positioned to protect it

Equipment
-Goon 1 is wearing sunglasses, at night. Uh, NO.
-His "body armor" is skewed and ill fitting.
-Neither Goon is wearing soft armor, just the plate carrier.
-Goon 1 has no Police ID on his back
-Their gear is loose and flops around

Subject
He immediately complies. Despite never being addressed by the Goons. They never say anything like, "Hey you!" They never point at him specifically.
He never says his name, never looks at the camera, never looks at Protester 1
He never exhibits stress. He's too calm

The Goons approach without face coverings and only put them in place once across the street. They don't exhibit signs of stress or adrenaline.
This will sound strange, but they don't walk like operators

There's no doubt that there are federal police operating in Oregon. But these Goons aren't them.

Assumptions
There are many mentions of NLG, National Lawyers Guild. Maybe this is a commercial for them or an attempt to discredit them

It could be an extraction of an agent provocateur, but if that's the case, why not just wait? The streets are empty. he could have easily slipped away to be picked up later.

There are all kinds of theories flying around

It could be a video made to illustrate what's happening in Portland, for either side. The message:
"Be careful the government is doing this, here's proof"
or
"Don't protest or we'll get you."

Without context or info about who made the video, it's purpose will be pure speculation