A teenager from Andover has been arrested connection with a string of hoax bomb threats to schools in the UK and US.
The National Crime Agency say they arrested the 18 year old at the home he shares with his family, on suspicion of making threats to kill, blackmail, and malicious communications.
He's on bail with conditions severely restricting his going online, and he's also being checked regularly to make sure he's keeping to them.
NCA senior investigating officer Marc Horsfall said, "The series of bomb threats caused huge worry and inconvenience to thousands of innocent people.
"Anyone thinking that law enforcement doesn't take such offences very seriously should really think again.
"Our investigation demonstrates we will do everything we can to find out who's behind the attacks and arrest them as soon as possible.
"Many cyber offenders believe they're well hidden behind their computer screens, but this arrest shows, we will identify you and come for you.
"We believe those arrested so far are all part of the same group. Other members and anyone thinking of joining them should bear that in mind.
"This is an ongoing investigation with more work to be done."
Hertfordshire Police and the NCA arrested an 18-year-old man in Watford on 21 March, two days after the original bomb threat.
He is on bail with conditions severely restricting his online use and he is subject to regular, no-notice checks that he is abiding by them.
Another 18-year-old man from Abbots Langley, Hertfordshire, was also arrested on 28 March on suspicion of making malicious communications.