Which is really easy for them because they're really friends with the powerful psychopaths running our planet. Most communes have been either assimilated or destroyed by the colonial powers that be.
See the ZAD in Notre-Dame-des-Landes or Exarchia in Athens for some of the latest examples of State power colonizing areas they had previously been consciously chased away from by the local population who just wanted independence from tyranny.
Many people have tried over the years. But only those that play nice with tyrants are allowed to survive. Hell even entire nations who did not bend to the wills of their colonial masters of yesteryear have been meddled with. See the assassination of Thomas Sankara (a democratically-elected president) as example of the dozens and dozens of US/Europe-powered coups d'État of the last decades.
Autonomous communes, whether squats or private property, have tried to declare their independence for centuries. The truth is they've been either assimilated or destroyed by Nation States. There's a very nice/powerful movie called La Cecilia about that.
La Cecilia 
It is allowed because the Order effectively predates the nation state as we currently know it today, and it is influential with one of the largest and most influential non governmental organisations ever, the Catholic Church.