Making bike thieves watch 30 seconds ads before they can disable the tracker would be vigilantism all right.
Knowing approximately where the bike is is only 1/3 of the battle. You still have to physically put your hands on it and remove it from whoever has it. I applaud the intent of a bike "lojack" but good luck getting the police to lift a finger when your bike tells you where it is.
That 50 bucks is better spent on a good U-lock upgrade.
Compared to those dramatic declines (and yes, 1993 was a pretty bad year for crime in the US, but that's the FBI's stats), motor vehicle theft has fallen off a cliff.
In 1993 there were 606 per 100,000 inhabitants. in 2012 there were 230. The new number is 38% of the old number.
I hear about fairly advanced car thefts in the UK all the time (RFID cloning, etc), but it's a problem that virtually doesn't exist anymore in the US in the eyes of car enthusiasts. (Yes, 20 year old Honda Accord parked in the ghetto is still a target. But modern vehicles in relatively good areas are simply not something we worry about anymore).
https://ucr.fbi.gov/crime-in-the-u.s/2012/crime-in-the-u.s.-...
Now it's parts. Wheels, airbags, bumpers, etc.
It's might be challenging to make something that is cheap, long range (for RFID) and tamper proof of course.
Why not just a low tech BIN (Bicycle version of a Vehicle ID Number (VIN)) stamped in the frame on the upright. You could also have a QR version printed. A traffic warden then could scan a rack of bikes and find any "reported stolen" ones.
Bikes with no QR would look suspicious and you could check the BIN (as would QR-BIN not matching bike style, colour, location). The BIN could be changed, but then so could an RFID chip (or a tracker); ground off frames would also look suspicious and warrant additional investigation.
?
You'd have to convince bike manufacturers to add BINs to bikes, which is likely against their financial interests as they probably sell more new bikes if bikes are more often stolen.
A GPS device on a bike will be the same thing. You can't embed it into the frame either, since you as the legitimate owner need to replace its battery every now and then, which means it needs to be easily removable.
If they are only effective against inexperienced car thieves, they still have value. It's like minor security measures that keep out script kiddies.
This worked for cars. Lojack, with their hidden transponder, caused a significant reduction in auto thefts. Lojack claims a 90% recovery rate. The main problem for bicycles is battery life. Someone needs to design a system which needs almost no power until the bicycle is stolen.
Lojack, which is a pre-GPS technology, does something like that. Their unit normally isn't transmitting. It's just listening to FM broadcast station subcarriers for its own serial number. When a car with Lojack is stolen, Lojack, which is plugged into police stolen car databases, has their FM stations broadcast the serial number repeatedly. The addressed Lojack unit wakes up and starts transmitting. Lojack makes a deal with police departments to put Lojack receivers in police cars. These light up when there's a transmitting stolen car in range.
You could do this today by connecting a digital pager to a GPS/GSM location transmitter. The GPS/GSM unit is normally off, and only turns on when the pager wakes it up. You can get six weeks of standby time on a digital pager easily. Add a power-from-motion device and you could probably keep the pager running indefinitely, as long as the bike gets some use.
OK, IoT crowd, get moving.
[1] https://www.amazon.com/Bicycle-GPS-Tracker-GPS305-Real-time/...