I had my kicker motor stolen while it was getting serviced at Olympic Boats in Fife. The theives cut a hole in the chain link fence, got into the boat yard and ended up breaking the handles off the kicker to get the motor.
What can ya do!
I now run a think nylon zip cable tie btwn the holes in the handle so they won't vibrate loose when underway.
When transporting the boat and in storage, I use a plastic coated cable lock from the motor to the tie down rings on the boat. The lock is made by "Cryptonite" or something like that, and is available in the hardware section at Walmart. The lock cost a litte, but you can't cut it with off with bolt cutters....