I ride mine...

First I'll try to ride away as fast as I can

Second I'll try to use my Cell to call 911 (or at least make it look like I am)

Third and only if all else fails...BIKE FOO!! A 40 Lb Mtb used as a swinging weapon can really do some damage,just ask the gangbanger that tryed to spoke me and take my bike in Tucson...after a trip to the hospital to get a batch of stiches on his head and his jaw reset,he got another ride to the county jail!!!