I'm concerned what could happen in the future, if large corporations have stored a lot of data. I was surprised how much civil liberties got eroded in the US af

I'm concerned what could happen in the future, if large corporations have stored a lot of data. I was surprised how much civil liberties got eroded in the US after 9/11. What if there are more big terrorist attacks, for example, and say the military takes over the government? Do you really want some central database of all the books you've ever read then?