It has a really good security system built in. When activated, it “locks” the wheels by applying reverse torque in whichever direction you attempt to drag it. The key is also a small device that communicates with the Segway cryptographically (pretty impressive for the early 2000’s!).

But mostly I think it’s because it was really heavy and perhaps novel enough. Nobody ever messed with it, even though the city I was living in was pretty bad in terms of crime rates.