Most smaller carriers in the U.S. don't actually own cell towers. Companies like Google Fi and Boost Mobile just rent space on the big three networks: AT&T, Verizon, and T-Mobile. So when the feds want your info, they usually go straight to these big guys. What can they see? Your call history, roughly where you've been (through cell towers), and your phone's ID number. If they want your actual texts or emails, they'd have to ask Google or whoever runs your messaging.

Will your carrier tell you? Probably not. AT&T, Verizon, and T-Mobile usually keep quiet unless a court forces them to speak up. Google Fi is a bit better - they might give you a heads up unless they're legally banned from doing so. Even without reading your messages, they can learn a lot just from the basics who you talk to, when, and where you go. Laws like the Patriot Act and CALEA make it pretty easy for them to get this stuff