For the record - Ree's moped mounts a small, low powered FM transmitter with a very, very long lasting battery....these are simple to build or aquire, and the proper batteries can make them last a couple of months.
There are quite a few places on a Moped to hide it, and the device is pretty small to begin with if you build it right or buy one from say, falcon enterprises.
Signal range is usually 1/2 mile even on a bad day, and often longer....even in a city, and that's pretty good, all in all for as small as it is.
The key to this, is that Ree has a signal meter that can be used as a direction-finder set to that Freq, in his closet...and will come looking the instant he notices his wheels are missing, on a 1/2mile range you can quarter a medium sized city rather thoroughly in under a day....and most folks who steal these things do not go very far with them anyhow.
What that means, is that if someone rips my 'ped...which would take a blowtorch since I tied it down six-ways-to-sunday with elevator cable and a pin-across lock - They had better be VERY far away very quickly, or they'll have a very upset ped-pusher in thier face real shortly.
I generally do not trust the police to retrive mine, not after one 'dissappeared' from impound when they were finishing the paperwork and due to give it back the next day...I bet some cops kid was real happy about his new toy <growl>.
The Kzoo cops are pretty good about it, but still, I will take it back myself...possibly handing out a few lumps in the exchange.
For those that have an interest, let me see if I can dig up some more info on where to get these gadgets.