Re: Possible ???
"Am i being too naive in thinking it is easy to find this data ?"
No. Our last telecommunications act shifted the ownership of call records from the customers to the telecoms industry. Lots of good data to be mined there. Never mind cell phone locations, if I can get a list of people that call the company switchboard (calling in sick, etc.) I can get a list of employees. And much of this information has moved offshore, beyond the reach of US laws governing sensitive material. When I call the phone company's customer service line, I usually hear a thick Hindi accent.
Anecdote: Back before the Internet was invented by Al Gore, I worked for Boeing. Lots of gov't stuff going on there in addition to commercial aircraft. We had (paper) company phone books which were updated about once every three months. And quite a few people took one home, in case they were off sick and needed to call in. All approved by management. When the new phone books came out, the old ones were just tossed into the trash. At home or at work. Free for the dumpster divers. The phone books had names, company phone numbers and organization/project numbers. So anyone with a keypunch, old school mainframe and time on their hands could have easily reverse engineered the companies entire project assignment structure. Given that we had quite a few domain experts working for us (and the KGB had dossiers on them and their skills as well), it would be pretty easy to figure out if a new group was being assembled for a particular task. And get a good idea whet they were up to. Absolutely no clue as to security on both Boeing's as well as the Pentagon's part.
In a subsequent job, which did involve high level clearances, I was told not to reveal even the name of the company I worked for. My CV is just a black hole for that period.