292
France grants police power to spy on citizens through phones
(www.techradar.com)
This is a most excellent place for technology news and articles.
It can't be done by a third party without extreme effort. This requires the cell phone manufacturer to participate along with the cellular service company as well.
Sorry for the late reply but I'd just like to warn you that it doesn't take a lot of effort. It takes some time, some knowledge of programming, electronics and communication protocols and a few hundred $$$ of equipment. DIY cell phone tower