A Purge island would work too. First offense of violent protest earns you a week there. 2nd Offense earns a month. No weapons, no cells, no beds, no gym, no guards, no food, no rules, NO ESCAPE. Bet you'd see leftists protests dry up over night. Televise the island carnage with drone cameras, and put all our worst violent offenders there too. It's ratings will CRUSH the Superbowl, Grammy's Oscars etc. Which isn't saying all that much.