The problem that I have with this device is that it places the onus on on women (just like every other rape-prevention technique) to stop their attackers. Men need to fucking learn that it is NOT ok to rape. Women DON'T like it. It isn't funny, and it isn't something that any woman, regardless of what she is wearing or how much she has been imbibing, is "asking for".
That will never hold up in court...