Four House Democrats on Monday suggested blacklisting or imposing sanctions against the Israeli firm that licensed spyware used by governments to hack the smartphones of journalists, human rights activists and business executives.

The Democrats’ statement was in response to an investigation by The Washington Post and 16 media partners into a list of phone numbers that included surveillance targets and that appeared to be concentrated in countries thought to have been clients of the NSO Group, a private spyware company based in Israel.

The findings reignited concerns about government surveillance carried out through technology provided by private companies.

“Enough is enough. The recent revelations regarding misuse of the NSO Group’s software reinforce our conviction that the hacking for hire industry must be brought under control,” Reps. Tom Malinowski (D-N.J.), Katie Porter (D-Calif.), Joaquin Castro (D-Tex.) and Anna G. Eshoo (D-Calif.) said in a joint statement.

An investigation by a consortium of media organizations has found that military-grade spyware licensed by an Israeli firm has been used to hack smartphones. (Jon Gerberg/The Washington Post)

The lawmakers added that companies that sell such tools to authoritarian regimes “should be sanctioned, and if necessary, shut down.” They called on the Commerce Department to consider adding the NSO Group and any companies engaged in similar behavior to its economic blacklist and to impose sanctions on its “abusive” clients under federal law.

Before publication of the investigation, known as the Pegasus Project, the NSO Group had called the probe’s findings exaggerated and baseless. The firm also said it does not operate the spyware it licenses to clients and “has no insight” into its specific use.

After publication, NSO co-founder Shalev Hulio said he was concerned by reports that journalists’ phones had been hacked and promised an investigation.

In their statement, the House Democrats also called for the federal government to investigate reports of the spyware being used to target American journalists, aid workers and diplomats overseas and to establish a “sanctions regime to hold accountable individuals and companies that sell these tools to authoritarian states.”