By not encrypting the call signs because unencrypted call signs aren't the problematic restriction. It's the content restrictions that are stifling in the modern world.

Also: progress has changed the landscape. HFDF used to be difficult for the military but now it's easy for hobbyists, and not just in last-mile form, but in coordinated always-on infrastructure form. The regulations were not written with this in mind. With an active community this fact alone might obviate the need for many a regulation.