Besides hacking I also love flight simulators and mountain biking. Last year I talked about hacking a flight simulator (and other games), it was time to target my other hobby.
Old days' speedometers evolved a lot, and a lot of bikers ride with computers that do much more than measuring speed: they have GPS, record activities, and communicate with sensors, mobile phones, and PCs.
One of the protocols used by them is ANT. Never heard of it? Not surprising, it is not very well known despite being used by a lot of gadgets including sport watches, mobile phones, and even bycicle lights.
I like weaknesses caused by bad design decisions, that can be found just by reading the docs. This happened here, I had attack vectors well before I got a bike GPS. After getting it, I have found some implementation bugs too.