Well that's just it, isn't it. I view this kind of thing as absolutely inevitable, but it can happen covertly, with unknown motives, no transparency, no checks and balances - or overtly, for the good of society and with transparency.
To me, the surveillance state is kind of the flip side of the war on drugs. Drugs are impossible to fight and we may as well just bring it out into the open and regulate it. Well, this is the government version - it will happen, so let's bring it into the light. It's happening anyway, and is as unstoppable as the technology which enables it. We may as well accept that, and have a mature conversation about how to manage it for the good of all.
Quite the opposite: the Five Eyes countries circumvent their laws against using their espionage agencies for domestic spying by handing the domestic data over to an ally for analysis. So the GCHQ spy on US citizens with the tacit agreement of the NSA and vice versa.