Group of hackers has hijacked tens of thousands of Google’s Chromecast streaming dongles, Google Home smart speakers and smart TVs with built-in Chromecast technology. The hackers exploited a design flaw in Chromecast that allowed them to access the devices and hijack their media streams to display a video message on connected televisions without authentication. Google was made aware of the bug multiple times since 2014 shortly after the streaming device was launched and acknowledged the hack, but the company has decided to ignore the issue.
Source: https://thehackernews.com/2019/01/chromecast-pewdiepie-hack.html