Our squad channel is known to dern near everyone and he wasnt invited but he constantly follows us and skuzzy wont do anything unless one is cheating the game its self. they wont do anything about spies. Several of us and others have spoke to him on the phone about it.
If you are using a public channel, then you are using it at your own risk. If you want privacy, then use the "Squad" channel provided in the game. If you insist on using a public channel, then it would be appropriate to cycle channels and not stay on one public channel.
Anyone can access a public channel. No squad can claim any of the public channels as private.