Fifteen people have been arrested across seven European countries “who are suspected of using remote access trojans (RATs) to commit cybercrimes,” Europol said in a statement on Thursday.

The people were apprehended in Estonia, France, Romania, Latvia, Italy, the United Kingdom, and Norway.

The National Crime Agency (NCA), a rough British equivalent to the FBI, lead a sting operation resulting in the arrests of five (out of the 15 total) across the United Kingdom. In May 2014, over 100 people were arrested as part of a similar worldwide sting operation.

As Ars has reported for years, RATs have been used to spy on Android phones, and individual PCs. They are often used to hijack women’s computers, which are then used to blackmail them into providing lewd videos or pictures of themselves.

“The illegal use of Remote Access Trojans is a significant cyber crime threat, demanding this kind of strong, coordinated response from international to local UK level,” Andy Archibald, deputy director of the NCA’s National Cyber Crime Unit, said in a statement on Friday. “Suspected users of RATs are continuing to find that, despite having no physical contact or interaction with their victims, they can still be identified, tracked down and arrested by the NCA and its partners.”