[kinkrtyavimoodh]

Is this a joke?

The US is EXTREMELY happy to collect taxes from people around the world and to call them resident aliens for tax purposes if they stay in the country for more than half a year or a given combination of days in the preceding 4-5 years.

[afwe]

Why aren't they kicked out? Why do people need green cards if they can stay?

[dragonwriter]

People with green cards, by definition, are not citizens.