Mobile phones have only been widely available for about sixteen years, but we’ve come to depend on them so heavily it is hard to remember what we did before we had them. If you have a smartphone, you carry a fully functional computer with a tremendous amount of personal information that is available at your fingertips – and to anyone else who can access it.

Senator Edward Markey (D-Mass) recently released information about the law enforcement agency requests to major mobile phone carriers including Verizon Wireless, AT&T, Sprint, T-Mobile, C Spire, US Cellular and Cricket Communications/Leap Wireless. The details Markey provided included numbers dialed, location data and even the contents of communication.

“As law enforcement uses new technology to protect the public from harm, we also must protect the information of innocent Americans from misuse,” he said in a statement. “We need a Fourth Amendment for the 21st century.”

Reportedly, Markey requested the reports from seven carriers as part of an audit, which was an update to a similar audit that took place one year earlier. According to The New York Times, most of the requests were for information from specific customer accounts, but law enforcement agencies also received information including data from 9,000 “tower dumps,” in which the agencies were provided access to data from all the handsets that connected to a cellular site.

“Disclosure of personal information from wireless devices raises significant legal and privacy concerns, particularly for innocent consumers,” said Markey. “That is why I plan to introduce legislation so that Americans can have confidence that their information is protected and standards are in place for the retention and disposal of this sensitive data.”

In fact, there were 1.1 million requests by law enforcement agencies for phone data in 2012, which was actually down from the 1.3 million requests made a year earlier. However, the number of requests in 2012 also fell as Sprint, the third-largest American carrier, did not answer all of Markey’s questions.

Additionally, some carriers were more heavily targeted by law enforcement than others. Specifically, T-Mobile appeared to cater to customers who are interesting to law enforcement given that they get the same number of requests as AT&T but have a third of the customer base.

The website PrivacySOS now provides charts about how long the carriers hold on to user data as well as information on the legal requirements for law enforcement agency access. In many cases, Markey found that it is just as often local police as it is government agencies that are requesting this data.

“This isn’t the NSA asking for information,” Markey told the Washington Post. “It’s your neighborhood police department requesting your mobile phone data. So there are serious questions about how law enforcement handles the information of innocent people swept up in these digital dragnets.”

For more information on data protection, check out the following:

New robocall regulations likely to spark deluge of litigation

HIPAA in conflict with ACA

Bring your own discovery nightmare: Inside counsel in the BYOD era