I have handcuffs. Years ago as a young retail manager we were taught how to apprehend shoplifters. The 5 elements of an arrest, how to detain, the proper application of handcuffs. At that time we were authorized to detain and use them. Of course the retail world has completely changed since that time. I no longer take the handcuffs out of the house as I do not see it as necessary or part of my job. I have kept them near my home defense shotgun for years now.
TriggerDr, you are correct. The misapplication of cuffs can backfire on you. I also think carrying them around unless you are LEO or trained security would be goofy.