Here's a couple of options.
Remove the feet, drill through the dock, and bolt to the dock from underneath using the sockets the feet normally thread into. This should discourage most people.
Lag screw through the bottom of the smoker into the dock. Put a hasp and lock on the door so you can store the smoke generator in the smoker and keep the folks who think they deserve your stuff more than you do from getting at the heads on the lag screws.
If you want to leave your smoker generator mounted in the normal position, drill a couple of holes in the edges to the puck chute and bolt a couple of pieces of all thread through the holes. That'll keep anyone from being able to pull the smoker generator out of the smoker. A couple of small C clamps would do the same thing, but you'd need to keep and eye on them to make sure they stayed tight.
