This is from The Blank Slate by Steven Pinker (H/T to Ex-Army).
First, open borders libertarians/anarchists have no sense whatsoever. Which means they have no understanding whatsoever of human nature, and therefore put theory above fact.
"When law enforcement vanishes, all manner of violence breaks out: looting, settling old scores, ethnic cleansing, and petty warfare among gangs, warlords and mafias. This was obvious in the remnants of Yugoslavia, the Soviet Union, and parts of Africa in the 1990s, but can also happen in countries with a long tradition of civility. As a young teenager in proudly peaceable Canada during the romantic 1960s, I was a true believer in Bakunin’s anarchism. I laughed off my parents’ argument that if the government ever laid down its arms all hell would break loose. Our competing predictions were put to the test at 8:00 A.M. on October 17, 1969, when the Montreal police went on strike. By 11:20 A.M. the first bank was robbed. By noon most downtown stores had closed because of looting. Within a few more hours, taxi drivers burned down the garage of a limousine service that had competed with them for airport customers, a rooftop sniper killed a provincial police officer, rioters broke into several hotels and restaurants, and a doctor slew a burglar in his suburban home. By the end of the day, six banks had been robbed, a hundred shops had been looted, twelve fires had been set, forty carloads of storefront glass had been broken, and three million dollars in property damage had been inflicted, before city authorities had to call in the army and, of course, the Mounties to restore order. This decisive empirical test left my politics in tatters (and offered a foretaste of life as a scientist)."