I’ve long said that every retail worker should be legally allowed to physically fight ten customers per year. And not a calendar year, where all the employees would be out of fights by the time holiday shopping season rolled around (or would be forced to save all of their fights for the holiday season). Give them ten points, and each point takes a year to fall off of their record once it is used. And the retail employee would have zero obligation to tell the customer if they have any points. Leave the customer guessing until the employee swings on them.

As gun nuts are so fond of saying: An armed society is a polite society. I think it would solve a lot of the problems with Karens. Karens only go full Karen because they hold all of the power in the relationship. But the threat of potential violence would go a long way towards quelling the most unreasonable ones, and people would only bother going full Karen if they truly felt they were justified and were willing to back it up with a fight.