Mobile phones generate an enormous amount of data about their users. This includes data you would expect, such as the numbers you called and the length of telephone calls.
But the information stored also includes data you might not expect, such as the particular cell phone tower to which you were connected during a call, which can help someone prove your location at a given time.
For example, I once had a case where the Defendant argued that he could not possibly have been personally served with a Complaint in Georgia on a given day, because he claimed to have been in Florida at the time.
But when the attorneys requested the cell phone tower data for the Defendant’s cell phone on that day, the data showed multiple calls made on the cell phone from the very area where service was made. Needless to say, the judge’s view of the “alibi” was severely impacted !
The ACLU has obtained a chart called Retention Periods of Major Cellular Providers from the Justice Department through a Freedom of Information Act (FOIA) request. It includes the retention periods for Verizon, T-Mobile, AT&T / Cingular, Sprint, Nextel, and Virgin Mobile.
It is possible to obtain these types of records from the phone companies during discovery. But, as the chart indicates, you probably need to act quickly to preserve some types of data.