The US police paid telecommunication companies over $26m (£15.8m) to provide consumer location data, metadata and messages in 2012, according to a report by the American Civil Liberties Union (ACLU).
Last year, AT&T and T-Mobile processed 600,000 requests for customer data from local, state, and federal law enforcement,
ACLU Washington Legislative Office legislative counsel Christopher Calabrese said police see citizens' mobile devices as the go-to source for information because of the lack of privacy protections afforded by the law.
"Our mobile devices quite literally store our most intimate thoughts as well as the details of our personal lives," Calabrese said.
"The idea that police can obtain such a rich treasure trove of data about any one of us without appropriate judicial oversight should send shivers down our spines."
In response to an investigation by Senator Edward Markey, Verizon revealed that police requests for consumers' call records have nearly doubled over the last five years
Markey said police sought over 9,000 dumps of cell tower data in which every device in range of a base station is logged, warning this could mean about tens of thousands more Americans were snooped.
US member of the Commerce, Science and Transportation Committee Senator Edward Markey said:"We need a 4th amendment for the 21st century. Disclosure of personal information from wireless devices raises significant legal and privacy concerns, particularly for innocent consumers.
"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."
The investigation also revealed that law enforcement performs real-time surveillance of targets' web browsing habits.
"There is an easy fix to part of this problem," Calabrese added.
"President Obama and members of Congress should pass legislation that updates our outdated privacy laws by requiring law enforcement to get a probable cause warrant before service providers disclose the contents of our electronic communications to the government.
"Anything less is unnecessarily invasive and un-American."