After robots replaced most workers the Congress wrote ever more severe laws punishing the "lazy" unemployed for not having jobs.
Eventually being poor, which they reasoned demonstrated anti-social attitudes, was made a felony. To reduce the increased costs of operating new prisons, repeat offenders were deemed incorrigible. The robot executioners stayed busy.
Getting rid of the poor people solved many problems. The world returned to environmental sustainability. Of course those who unwisely over invested in prisons and fossil fuels became poor and were put down.
It was a black Friday when the stock market tanked, taking humanity with it.