LONDON (AP) – An extremist who concealed information in USB-equipped cufflinks has been jailed for eight years in London.

Samata Ullah was sentenced at the Old Bailey courthouse Tuesday. He had pleaded guilty to five offenses in March and admitted membership in the Islamic State group.

Testimony indicated that he advised other extremists how to manage data without being caught and told them not to put information on computers but to use USB sticks instead.

His cufflinks contained a Linux operating system loaded with extremist data, including a blog.

Metropolitan Police Commander Dean Haydon said Ullah “set up a self-help library for terrorists around the world.”

He said Ullah advised extremists on how best to encrypt data.