It's worth reading Beyond Snowden which is written by Timothy Edgar, a former ACLU lawyer who got hired into the Obama administration as a PCL advisor and event

It's worth reading Beyond Snowden which is written by Timothy Edgar, a former ACLU lawyer who got hired into the Obama administration as a PCL advisor and eventually worked at the NSA. He gives a lot of insight into how things actually work with a deep understanding of the issues and the difficulty around these policy tradeoffs. The organizations do take oversight seriously, but there's still a risk of 'turn key tyranny' and there are improvements that can be made. It's possible to have security and civil liberties, but you need effective policy and it can't happen in secret.