Company will also send warnings to 48,000 people believed to be targeted by malicious activity after investigation

Facebook has banned seven “surveillance-for-hire” companies from its platforms and will send warning notices to 48,000 people who the company believes were targeted by malicious activity, following a months-long investigation into the “cyber mercenary” industry.

The social media company said on Thursday that its investigation had revealed new details about the way the surveillance companies enable their clients to “indiscriminately” target people across the internet to collect intelligence about them, manipulate them – and ultimately compromise their devices.

Black Cube, an Israeli company that gained notoriety after it emerged that the disgraced media mogul and convicted sex offender Harvey Weinstein had hired them to target women who had accused him of abuse. Black Cube rejected Facebook’s claims about its activities.

Cobwebs, another Israeli company that Facebook said enabled its clients to use public websites and dark web sites to trick targets into revealing personal information. The company also reportedly works for US clients, including a local police department in Hartford, Connecticut.

Cytrox, a North Macedonian company that Facebook said enabled its clients to infect targets with malware following phishing campaigns.