don't have too much of an issue with the rubber bands, the ones I do worry about is the "I've been to a festival" wrist bands that then have a metal clip.
I would with the rubber ones. I don't know how strong they are, but I can the potential for a finger getting caught in one. Then, one of two things will give way: the band, or the finger.
they'd snap if you give them a good tug, but agree they'd pop a finger if it got caught, but no worse that getting a digit stuck in a pocket or shirt collar.
When I used to do soccer, I had a player end up with a dislocated finger after a close encounter with a rubber wristband. I wish I'd got that bloke's number so I could refer everyone else who whinged at me for making them take them off to him.