You can monitor verizon cell phones online at verizonwireless.com
Once you log in, you can view either "my bill" which gives the details (voice, messages, data) for each phone number on the account or you can check "view my usage". This one gives most recent information since the last bill. It does have about a 24 hour delay in the details. You cannot read the text messages, but it does contain the number, whether it was sent or received, and general location of the call. On the voice calls, it also gives the time of the call, the length of the call and whether the call was placed or incoming.
This was how I busted my H's A. The phone bill arrived in the mail and listed 128 text messages in a month. I knew they were not to me. I went to the website, got the details for his phone, called the number, got the OW's voicemail. Next I did a reverse lookup, found the home phone and called OW's H, downloaded and printed out all the phone info, and emailed it to OW's H. Took less than 2 hours to do all that. Then I called H, H's mom, counseling listing service for the military. The PA part of the affair stopped immediately; took the next three months, change of job and move to a different state to put NC in place.
Amazingly, a few weeks after D-day, my phone broke. When I was changing it out at the verizon store, I started a conversation with a total stranger who was suspicious her H was having an A. The verizon people weren't giving her much help about how to do this, but I sure did. I prefer action to inaction.
BTW D-day plus 7.75 months, I check the online verizon details every few days. I am really BIG on verification, especially now around the holidays.
AM