Actually, the paranoia is probably worse than the chance of theft since I rarely leave the bike out of sight. Two weeks ago, we went on a out-of-town trip with the bike on a hitch rack. That was when I felt most vulnerable and I did not have the device then. The bike was on the rack when we walked away twice to check out restaurants and I admit I was uncomfortable but did not have this device yet. But then again, the bike was still there. It is a Kuat rack and has a cable which did wrap the bike. But we know how durable cables are - NOT! Then closer to home we stopped at an art gallery and the bike was out on the street and boy, was I uncomfortable. So I added a chain and u-lock
The last bike I had stolen was when I was about 15 and it was in an apartment building basement in the Bronx! That was many, many years ago.