It's not about people's safety, it's about politicians' safety. See my comment https://news.ycombinator.com/item?id=45331829

Of course they don't need to spy on themselves. The goal is to stop targeted attacks against politicians and any attempts to overthrow the government. The government is uniquely unlikely to overthrow itself.

Empirically that’s absurd. The US is currently undergoing an internal struggle that’s exemplified by the agents of change being part of the government AND dangerously hostile to opposition.