As Radio Insight explains, hardware left unprotected by firewalls and with default passwords can easily be exploited remotely. The Michigan Association of Broadcasters has information on how the devices can be secured, but if they aren't, then we can expect to keep hearing about incidents like this. The Shodan search engine makes it trivially easy to find vulnerable connected hardware, so make sure your hardware (security cameras, refrigerators, TVs, whatever) is set up properly and ports aren't exposed to the internet.