Too much faith in technology

from here and here

A networking failure shouldn't cause lights to get stuck in the ON position, and not anticipating those kinds of failures in your design is a pretty good indication that you didn't anticipate malicious misuse either. A good engineer anticipates failure. A good security engineer also anticipates malicious misuse. There are probably a number of security vulnerabilities in the system in addition to this lighting control DoS.

Another reason to take a dim view of smart bulbs

from here

Smart light bulbs that store your WiFi password are kind of problematic. When you throw it out it still remembers that password and other people may be able to retrieve it. Obviously that isn't ideal, but that's a symptom of a bigger problem. Many (maybe all) smart devices are going to remember your WiFi password and we are introducing them into an established culture of disposable consumerism, where old things are regularly thrown out and replaced with new ones. I freely admit that I never really appreciated the problem of security waste (forget e-waste, now we'll have s-waste) before, but as more and more things become smart, our garbage will contain more and more of our passwords. That's a disturbing attack surface. I don't know if we're really ready for the consequences of the Internet of Disposable Things.