Psh, you can still spread messages person to person, you know, in REAL LIFE. It's sad how we're all tied to the Internet and try to make it the first and foremost way in which we communicate.
Most governments only go to controlling online activity after controlling real-life activity. I don't know about Pakistan specifically, but typically the domestic "security" organizations are rather adept at tracking down groups who organize in meatspace.
Why do the cops win? A network of instant communication. If you can't communicate quickly, or at least as fast as your enemies, in many cases you might as well not communicate at all. There are benefits of sneakernets but they don't win on their own.
