Individual privacy and security is national security.

The “nation” in anything resembling a democracy is made up of individual private people with their own motivations, and their own sometimes considerable power, whose security is protected even when it doesn’t line up with the interests of whoever happens to be in charge of the government. Those nations can become extremely powerful, much more so than “secure” states, because they have within them powerful people who give good faith to the systems of government that can organize and wield state power. It has to be that way. Any government that betrays that relationship will collapse into something akin to modern-day Russia. Certain policies might be bad for “individual privacy” in the short run, and good for “national security” in the short run, but there’s a reason why the nations of Nazi Germany or the USSR who prioritized state security so high above that of individuals, weren’t at all secure in practice. On an individual or a national level.

In the absolute middle of World War 2, when Britain was fighting literally for its life against the literal Nazis, and losing, the government had to deal with paying rent to the sometimes disagreeable landlords for their military intelligence offices, and they had to face angry questions from civilians in government about firebombing in German cities and how it was inhumane. They weren’t allowed to just get on with whatever they decided they wanted to do. There was no question about “well this is a government matter so I don’t care what you think, as a private person, and I don’t have to.” That’s not how a democracy works. Some people might disagree, but in my opinion that’s why the side that Britain was part of ultimately won the war: Because the British people knew their rights as individuals would be respected, and so they in turn felt comfortable giving wholehearted support back to the government when the government needed it.

Anyone who describes “national security” as a thing that has to be balanced against the rights of the people who in actual reality make up the nation, is probably talking about something more akin to “state security” in the USSR or Nazi sense. Not the security of the actual nation, but the safety and convenience of policymakers and their friends, sometimes specifically their safety from the nation (i.e. the people).