They do it here in Thailand. Last year they set a cutoff date - if you had not registered your SIM + gov issued id by a certain date your service was cutoff and you couldn't get new service until you did. The reason was "terrorism", because southern insurgents kept using cell phones as remotes to set off bombs. Now the government uses the information to round up pesky people who use chat apps on their phones to organize protests against the military junta. That's the pattern, right? Start with /terrorism/think of the children/war on drugs/ and transition to general oppression of the populace.