Democrats seek answers on high-tech surveillance of protesters by U.S. agencies

Congressional Democrats are probing the possible use of high-tech surveillance tools by federal law enforcement agencies to monitor protesters at nationwide marches against police brutality.

House Democrats have in recent days sent letters to the FBI, Drug Enforcement Administration, the National Guard Bureau, Customs and Border Protection and the Defense Department seeking to understand whether authorities have deployed powerful tools like facial recognition and cell phone data-tracking against protesters.

And Sen. Edward J. Markey, D-Mass., on Monday sent a list of questions to Clearview AI, the controversial facial recognition technology company that partners with law enforcement agencies and private companies,