[Bloody Sam Roberts]

I was part of a project to explore this technology a year and a half ago when this was first planned and one of things that needs to be realized is that this information is real time. Law enforcement agencies can get access to it but no one else can. And even if they could, it is not stored for very long. It can't be. These systems generate a huge amount of data. In order to store this information for a longer time would require the cellular carriers to make huge expenditures in data storage infrastructure hardware and software...with no return on these expenditures.
If, for example you are afraid your employer will find out that you visited an AIDS clinic because your cellphone was in your pocket and powered on at the time...relax. Even if the information was stored somewhere, your employer would need a court order to get to it.

[Mulder]

These systems generate a huge amount of data. In order to store this information for a longer time would require the cellular carriers to make huge expenditures in data storage infrastructure hardware and software...with no return on these expenditures.

So the federal gov't will store it.

Also, I think the data storage requirements are a lot less than most people think.