Your personal security is unrelated to the security in that argument. The idea is that the nation can't protect itself if there are secrets it lacks access to.

Your personal security is unrelated to the security in that argument. The idea is that the nation can't protect itself if there are secrets it lacks access to. They want to spy on (potential) foreign forces within the country. To do so, the privacy of your home would be sacrificed in the name of the security of your country.