The use of "stingrays" that capture data about cell phone calls has become increasingly controversial, but law enforcement agencies continue to embrace the devices. Just last week, IRS Director John Koskinen was questioned in the US Senate about his agency's acquisition of a stingray for its criminal investigations.

Today, Rep. Jason Chaffetz (R-Utah) has said he'll introduce a bill that will criminalize any use of a stingray without a warrant. He provided a draft copy of the bill to the Washington Examiner, which reports that violations would be punishable by a fine and up to 10 years in prison.

The bill (PDF) includes wide exemptions for situations involving "emergencies that include an 'immediate danger of death,' national security or ... the Foreign Intelligence Surveillance Act," according to the Examiner.

The Chaffetz bill would apply to state and local agencies as well as federal ones. The American Civil Liberties Union has identified 57 agencies that own stingrays or similar devices in 22 states and the District of Columbia.

“The abuse of Stingrays and other cell site simulators by individuals, including law enforcement, could enable gross violations of privacy,” said Chaffetz in a statement on his introduction of the bill. "The fact that law enforcement agencies, and non-law enforcement agencies such as the IRS, have invested in these devices raises serious questions about who is using this technology and why. These questions demonstrate the need for strict guidelines that carry the weight of the law."

Stingrays operate by imitating a cell-phone tower and collecting location information about nearby phones. In some cases, they can also collect text message and call data.

Under Senate questioning last week, Koskinen emphasized that his agency already gets a warrant when it uses the device. "It does not allow you to overhear... voice communications," he added. "You may pick up texting." Koskinen was unable to provide the number of times that stingrays had been used by the IRS, but he said he would provide answers in writing within 30 days.

Chaffetz and other House Republicans already have a serious beef with IRS chief Koskinen. They're seeking to impeach him for his agency's targeting of conservative groups that sought tax exemptions.