Ashkan Soltani, the FTC’s Chief Technologist, penned a good article on the particular security challenges of cheap, connected, low-power devices. He uses the venerable refrigerator example to get some important questions across:

… a refrigerator was once just a refrigerator with one purpose: cooling food. Now that we live in an IoT world, embedded inside that refrigerator is a full-fledged network computer which could potentially be exploited to launch a DDOS attack against the consumer (or some external) network. As the technology behind the household items we buy evolves, so must the way we think about the long-term effect to consumers when they purchase them:

What will be the level of security and support while under warranty? If a critical vulnerability is discovered, will an update be provided? What happens after the warranty expires? Should modern refrigerators have a shelf-life, much like the food contained within?

http://www.ftc.gov/news-events/blogs/techftc/2015/02/whats-security-shelf-life-iot