A hacker hijacked more than 50,000 internet-connected printers worldwide to print out flyers asking everyone to subscribe to PewDiePie YouTube channel. The hacker mainly uses an open-source hacking tool to exploit vulnerable printers, called TheHackerGiraffe. The message urged hack victims to unsubscribe from T-Series channel and subscribe to the channel instead. The channel owned by Bollywood record label T-series has been catching up in recent months, and now both are hovering around 72.5 million YouTube subscribers.
Source: https://thehackernews.com/2018/11/pewdiepie-printer-hack.html

