They haven't changed. They won't fall off usually, but they will pop off if you catch them on something or apply pressure just the right way. DD's popped off a couple of times when she caught or knocked it on something, but she always felt it and caught it. I think DH's popped off when he picked her up once. I've heard that picking up and putting down kids tends to be a time when they pop off quite a bit. We found one in the pool and turned it in- I'm guessing the current of swimming properly got it. I'd say just always make sure they are still on everyone's wrist when you leave a pool area. Other than that, it isn't a big problem, but just kind of be aware of the possibility. We had just a few pop offs during our 8 day stay.