Think I'm pretty careful with my camera bag, so I'm not too worried about it being nicked.
In regards to a bike though, I think the problem is that if it does get nicked, you are probably going to end up tracking it to some huge sprawling estate with no way of even knowing which property it is in. A lot like some of the cases where people have tracked their Apple devices, the Police probably won't have the time, so you are best just going to your insurance company.