>> Now I don't quite get this. Are they going to store these millions of emails, texts, etc, search them all, and look for baddies ?
As far as I can tell they don't save the content of these phone calls, email, etc - they just save who contacts who, when folks contact each other etc. From this they can see who a suspect of theirs talks to/emails, how often and then see who those acquaintances talk to and email.
They don't save all the conversations and specific details, or so they tell us...
