The U.S. government wants to know the extent to which criminals and foreign spies are using “Stingrays” against Americans.

A task force has been set up by the Federal Communications Commission to study how electronic surveillance devices, including those that are commercially available, are being used to electronically follow Americans, eavesdropping on phone calls and infecting devices with malware.

The particular focus of the FCC’s interest is the so-called Stingray, a platform also known as a IMSI catcher that intercepts mobile phone traffic. It is used by law enforcement and intelligent agencies worldwide to intercept unencrypted cellular traffic and is hard to detect. The Stingray is produced by IT companies who provide them to U.S spies, cops and other foreign clients.

IMSI stands for International Mobile Subscriber Identity.

The FCC has established a task force to study how these groups are using them against targets in the U.S. FCC chairman Tom Wheeler said in a letter earlier in August that his agency has the authority to study the the issue in order to ascertain who’s using Stingrays illegally and for what purposes, the Washington Post reported.

Wheeler said the task force was mobilized, in part, by Democratic Rep. Alan M. Grayson’s concerns on the issue, specifically how these devices are being turned against U.S. citizens and the authorities themselves. The objective of the task force, Wheeler said, is “to develop concrete solutions to protect the cellular network systemically from similar unlawful intrusions and interceptions.”

Stingrays work by obtaining the IMSI’s target cell number. The Stingray then mimics the nearest cell tower so the targeted phone re-route communications through the Stingray instead. This kind of intercept is also known as a “man in the middle,” or MITM, attack.

The drawback for those using Stingrays is that if the target is using sophisticated encryption, the intercepts are rendered nearly useless.

Stingrays are about the size of a small suitcase. Commercial variants can be purchased by the public granted one knows where to look.