The head of the US intelligence community has acknowledged for the first time that American spy agencies might use a new generation of smart household devices to increase their surveillance capabilities. James Clapper, the Director of National Intelligence, made the remarks on Tuesday during a testimony before the Senate Armed Services and Intelligence Committees as part of an assessment of threats facing the United States. “In the future, intelligence services might use the [Internet of Things] for identification, surveillance, monitoring, location tracking, and targeting for recruitment, or to gain access to networks or user credentials,” Clapper said.

The Internet of Things is the network of physical objects—devices, vehicles, buildings and other items which are embedded with electronics, software, sensors, and network connectivity, which enables these objects to collect and exchange data.

Clapper did not specifically name any intelligence agency as involved in the surveillance of household devices. But technology experts and privacy advocates examining the Internet of Things believe that US surveillance agencies will intercept the signals the newly networked devices emit, much as they do with those from mobile phones.

The experts warn that thousands of completely unsecured web-connected devices are currently used by customers.

The US National Security Agency (NSA) has previously come under fire for secretly spying on Americans’ phone calls and internet communications. NSA’s mass espionage program was first leaked in 2013 by the agency’s former contractor Edward Snowden.

During Tuesday’s Senate hearing, Clapper also warned that fast-moving cyber and technological advances “could lead to widespread vulnerabilities in civilian infrastructures and US government systems.” “In my 50 plus years in the intelligence business I cannot recall a more diverse array of crises and challenges than we face today,” Clapper said.

Attacks by “homegrown” extremists are among the most imminent security threats facing the United States in 2016, Clapper argued. The Daesh (ISIL) terrorist group poses the biggest danger among militant groups because of the territory it controls in Iraq and Syria, and is determined to launch attacks on US soil, Clapper said. Daesh has also has demonstrated “unprecedented online proficiencies,” he added.

He also cited threats from Russia’s increasingly assertive international policies, saying “We could be into another Cold War-like spiral.”