A man has been jailed for sending a "potentially lethal homemade bomb" to a Bitcoin firm in London - after it refused to reset his password for him.
The Met Police, which investigated the case, said detectives could "only identify one possible reason" for the Swedish national's actions.
He had emailed the company, Cryptopay, in August 2017, to ask that he be sent a new password.
Jermu Michael Salonen, 43, has been sentenced to six-and-a-half years in prison at Stockholm District Court.
He faced a number of charges, including some for sending a white powder to Swedish lawmakers - among them, the prime minister - in 2017.
Salonen had addressed a padded envelope containing the device to two Cryptopay employees.
It was delivered at some point in November 2017 to an office in Hackney, which had housed an accountancy firm previously used by Cryptopay.
Several months later, on 8 March 2018, a worker at the office began opening the package but did not continue when they became suspicious of what was inside.
"We are relieved that no one from The Accountancy Cloud team was hurt in this incident," a spokesman for Cryptopay told the BBC. "None of our employees have ever worked at that address."
"The vast majority of our employees work remotely across Europe, but we are implementing additional security measures to prevent any potential harm to our employees anyway.
"We are thankful for both British and Swedish police, who were able to investigate the case with outstanding professionalism."
"It was due to sheer luck that the recipient ripped opened the package in the middle rather than using the envelope flap which would have activated the device," said Commander Clarke Jarrett at the Met Police Counter Terrorism Command.
DNA found in the package did not match information on UK databases, so it was analysed by Interpol.
"Through these inquiries, it was identified that the DNA matched those of Salonen, who was known to Swedish authorities," the Met says.
A search of Salonen's home discovered "numerous bomb components".