a notice on every device says:
- texting, email, socials is over
- communication with others is over
- employment is over
- public assembly illegal
- leaving your area is illegal
- food production is halted
- robots will enforce the new law & order
- they kill immediately
- other robots arrive, grind the corpses, and removed the boxed remains within a minute
- soon they start entering homes

the robots are just cylinders, they don't even look cool
life is over for everyone except the 0.0000001%
tech keeps them alive and healthy forever
no one saw it coming.

it worked perfectly

in weeks Earth is a paradise for the richest people who ever lived
Population: a few dozen