The House Committee on Homeland Security urged Google and Apple to remove apps that let people track federal immigration agents after a rise in violence against law enforcement across the nation.

Committee Chairman Andrew R. Garbarino (R-N.Y.) and Accountability Chairman Josh Brecheen (R-Okla.) sent letters on Dec. 5 to Google CEO Sundar Pichai and Apple head Tim Cook, voicing concerns about the officer-tracking technology.

“The Committee on Homeland Security is investigating mobile applications (apps) potentially hosted by [Apple and Google] that enable users to anonymously report and track the movement of federal law enforcement, including U.S. Customs and Border Protection (CBP), U.S. Immigration and Customs Enforcement (ICE), and other U.S. Department of Homeland Security (DHS) officials,” the letters claimed.

“The Committee is concerned that these apps not only jeopardize the safety of DHS personnel but also enable malicious actors to incite violence and obstruct lawful government operations.”

Lawmakers specifically called out an app called ICEBlock, which can be used to report the location and identification of DHS personnel.

ICEBlock was used by a gunman who tracked the movements of ICE before a deadly shooting at an ICE facility in Dallas on Sept. 24.

One detainee was killed, two others were wounded, and the shooter, 29-year-old Joshua Jahn, died of a self-inflicted gunshot wound.

ICEBlock was removed from all platforms weeks later.

Lawmakers in Washington said more needs to be done.

“[Apple’s App Store and Google’s Play Store host] apps that allow users to report and disseminate data to reveal the location and identification of DHS law enforcement and their movements,” Friday’s statement continued.

“These tools risk the safety of these officers, their families, and the operations they are conducting.”

The committee reiterated that it fully supported all Americans’ right to free speech, however, “that right is not absolute.”

“Accordingly, the U.S. Supreme Court in Brandenburg v. Ohio ruled: ‘Freedoms of speech and press do not permit a State to forbid advocacy of the use of force or of law violation except where such advocacy is directed to inciting or producing imminent lawless action and is likely to incite or produce such action,’” the statement continued.

The committee also requested that Apple and Google explain how each company is working to monitor and remove apps that track immigration officers.

“The Committee seeks to better understand what measures [Apple and Google are] taking to remove these types of apps from the [Apple’s App Store and Google Play Store] and to ensure that they are not used to endanger the safety of federal law enforcement officers or interfere with the legal execution of federal immigration enforcement,” the statement concluded.