I used to work for AT&T as a customer service agent. While I did not have direct access to this system, we did have a company proprietary tool that allows us to see texts/calls/internet search history on any phone connecting to our network. It could only be accessed after speaking with a direct supervisor. We were never allowed to tell customers we could access it.
With that being said... the police absolutely do not care what is on your phone provided it doesnt contain evidence of a serious crime, and even then it's only if you're distributing something you shouldnt.