A man has admitted carrying out a campaign of bomb hoaxes targeting the Palace of Westminster, the Super Bowl in the US and dozens of schools.
Andreas Dowling, 24, from Torpoint, in Cornwall, admitted 30 counts of communicating false information with intent between October 2014 and February 2016.
Bristol Crown Court heard that the 30 charges encompassed a total of 107 incidents of bomb hoaxes.
He will be sentenced at a later date.
Dowling, who is deaf, targeted around 70 schools in the UK and various locations in the US and Canada.
'Disruption and panic'
The court heard that one of the charges related to bomb threats made against Jewish schools and would be sentenced as "racially aggravated".
At a previous hearing at the Old Bailey, prosecutor Simon Laws QC said the hoaxes caused "disruption and panic" in the countries targeted and were made both online and by phone.
He threatened the Super Bowl, one of the biggest events in America's sporting calendar, on 1 February 2015.
Dowling also threatened the Houses of Parliament on February 8 2016.
He was arrested in June following an investigation by Counter Terrorism Policing South West.
Avon and Somerset Police said later that officers were satisfied the alleged bomb threats "were not an act of terrorism".
Deputy Assistant Commissioner Dean Haydon told the PA news agency, that police still do not know why Dowling committed the crimes.
"He was on a course to cause, if you like, disruption to those various locations," he said.
"But his motivation to this day, unfortunately, we don't know."
Rachael Scott, from the Crown Prosecution Service, said the "crucial bit of evidence" was found on Dowling's home computer.
"When police executed a warrant at his address in October 2017 they recovered a hard drive from his bedroom which basically confirmed that he was 'Janka', this person responsible on the internet for committing these offences," she said.