It would be like a tiny nanoalarm disguised as a button or belt buckle on a woman's pants and if forcfully pulled out or torn or misplaced a silent alarm will be activated and police will be alerted, also a set of earrings or hair clip that will act as a tracking device if you press a tiny button on it, so then the police will be able to find you. Women could wear them everytime they go out at night alone or to a bar or something.