As I understand it, they don't have the capability to essentially PCAP all that data.. and the data wouldn't be that useful since most interesting traffic is encrypted as well. Instead they store the metadata around the traffic. Phone number X made an outgoing call to Y @ timestamp A, call ended at timestamp B, approximate location is Z, etc. Repeat that for internet IP addresses do some analysis and then you can build a pretty interesting web of connections and how they interact.