If your society is not truly "opt-in", then Big Brother surveillance is the only real option for safety.
We (America) let tons of people into our country with all sorts of whacko beliefs (yes, blowing up buildings full of civilians defines you as a "whacko"), and we have lots of homegrown nutters too.
Being/becoming a "citizen" is easy, all citizens get the same rights, and everybody gets to vote.
Many people never display an iota of civil responsibility, yet they are granted the same "power" (rights + votes) as others who would sacrifice much or all to contribute to the common good.
If you make it tough to become a citizen, then all of a sudden you might not need to monitor citizens.