In Washington, a member of the U.S. Senate Intelligence committee asked three federal agencies what steps the government can take to prevent cyber criminals from compromising electronic devices.

In a new type of attack last Friday, hackers harnessed hundreds of thousands of webcams and other connected devices globally to flood U.S.-based internet infrastructure provider Dyn with so much traffic that it could not cope, cutting access to websites including PayPal (PYPL), Spotify, and Twitter (TWTR).

Hangzhou Xiongmai said it would recall some surveillance cameras sold in the United States after researchers identified they had been targeted in the attack.

Liu Yuexin, Xiongmai’s marketing director, estimated the number of vulnerable devices at fewer than 10,000 to be recalled. He said the company would recall the first few batches of surveillance cameras made in 2014 that monitor rooms or shops for personal, rather than industrial, use.

Xiongmai had now fixed loopholes in earlier products, prompting users to change default passwords and block telnet access, Liu said.

The U.S. Department of Homeland Security (DHS) said it had discussed the attacks with 18 major communications service providers and was working to develop a new set of “strategic principles” for securing internet-connected devices.

Authorities have yet to identify suspects in the attack, but the Director of U.S. National Intelligence, James Clapper, said on Tuesday that an early analysis did not point to a foreign government.

Cyber intelligence firm Flashpoint concurred.

“The evidence that we have strongly suggests it is amateur, attention-motivated hackers,” said Allison Nixon, Flashpoint’s director of security research.

Nixon said the same infrastructure was used on Friday in an unsuccessful attempt to disrupt internet access to a major video game manufacturer, which she declined to identify.

“Nation states generally don’t attack gaming companies,” she said.

U.S. Senate intelligence committee member Senator Mark Warner, a Democrat, sent letters on Tuesday asking DHS, the Federal Communications Commission (FCC) and Federal Trade Commission if they have adequate tools for combating the threat posed by “bot net” armies of infected electronic devices.

“Manufacturers today are flooding the market with cheap, insecure devices, with few market incentives to design the products with security in mind, or to provide ongoing support,” Warner said.

He asked FCC Chairman Tom Wheeler if communications providers have authority to deny internet access to electronics devices they deem insecure.

Xiongmai devices were unlikely to suffer similar attacks in China and elsewhere outside the United States, where they are typically used in more secure industrial networks, Liu said.

The company may take further steps to beef up security by migrating to safer operating systems and adding further encryption, Liu said.