A Morrisons supermarket auditor has been sentenced to eight years in prison after leaking the personal information of over 100,000 supermarket staff.

Andrew Skelton, 43, was convicted on charges of fraud, unauthorized access and disclosing personal data after he leaked the information in retaliation following his company chastising him for using the mailroom to send eBay packages. The resulting breach exposed salaries, insurance numbers, date of births, and bank account details and cost more than $3.1 million to rectify, according to Yorkshire Post.

The former auditor tried to cover his tracks by creating fraudulent accounts to implicate a coworker.

Skelton's personal use of the mailroom came to light in 2013 after his office received a package suspected of containing synthetic drugs. While the incident turned out to be a false alarm, it alerted his employer to his abuse of mailroom privileges.