I don't know if it's a hobbie. But it's a money pit. I am into home automation. I have nearly every switch in my house controlled via automaton. And I monitor every door lock and can control them.
I have my alarm tied to the automation system so each zone can trigger and influence a light or any other activity. 18 zones of 89 total sprinklers are each controlled by automation. Climate control is also controlled and their are the 12 HD 720 cameras around the property. Water and power are monitored and graphed. Each powered device has its own unique power signature that shows up in real-time.
There is a lot more going on but that is kind of a basic idea of my place. The money pit comes into play when you figure out that there is some sort new device coming on the market every day.
What about the power goes out?