The idea of ICE in cell phones was not a direct result of the London bombing. It's been floating around for some time. While the idea of having ICE on your person is a very good idea, it doesn't need to be this complicated. Just simply put a slip of paper in your wallet.Not everybody carries a cell phone.
Almost all cell phone users lock their phone with a PIN, preventing access.
My cell stops working if I look at it wrong. The odds of it surviving an "incident" that would put me unconscious is next to nil.
Like I said, great idea, but misdirected in execution to be more complicated than it needs to be.