I don't see why the Houses Militaries shouldn't be able to control who has their ships. In real life, no one calls it "fascism" when civilians can't pinch M1 Abrams tanks from US Army bases (and the US Air Force doesn't sell off F16 Raptors, nor does the Navy sell off Nimitz class carriers to the general public). No one calls the fact you can't buy NYPD badges on the black market and try and police New York City "oppressive" or "unfair". I've never heard anyone arguing in a US Court that the Constitution gives them a right to impersonate a CIA agent.
So why do the people here scream bloody murder when a faction decides to act like what it's supposed to roleplay?
If you have a problem with factions setting such restrictions, take it up with the admins. They are the ones allowing the continued existence of factions with unilateral names like "Liberty Security Force" or "Rheinland Military".
It's also a complete strawman to argue the factions are enforcing it like a server rule. It's a roleplay restriction, like busting people with cardamine. There's not a single military on this Earth that allows you to take it's vehicles or identification without it's permission and/or membership. If you can find me a military that allows that, I'll concede that last point.
But that's getting off topic. The real point here is the enforcement of regulations regarding Zone 21, and the main problems seem to be 'independents' (Indies is too cutesy for me) and manpower.