Recently, printers around the world started spewing out pages without any direction from their owners. Then a mysterious video showed up on smart TVs.

Both hacks were designed to promote PewDiePie, the most popular vlogger on YouTube, in his battle to maintain subscriber supremacy against popular Indian channel T-Series.

The hackers say they did it to expose the flaws and dangers in some connected devices, but they also got the attention of the YouTube star – as well as the authorities, and trolls who sent them threats.

The BBC’s cybersecurity correspondent Joe Tidy tracked down the hackers and joins us in the studio to tell us what he found out.

After the pranks make worldwide news, the pair decided to disappear from the internet for fear of reprisals. Do they now regret hacking?

Presenter: Anisa Subedar

(Photo Caption: YouTuber PewDiePie / Photo Credit: Getty Images)