This gives me mixed feelings.
As a victim of rape, I like the idea of "biting" a rapist's dick off and making him feel complete utter pain. Nothing would please me more than to see that happen.
However, rape is a purely situational thing. It could happen to any woman at any time given the right (wrong?) circumstances. At 2$ a piece for one of those and given it's only a one time use, that's a lot of money to be spending on something that could or could not happen. I mean if you're going on blind dates or clubbing or in a situation where you're uncomfortable with the general male population (I mean why the hell would you put yourself in those situations if you're uncomfy in the first place?) then I guess it'd be ok. I guess. *shrug*
But there are also rapes that happen when women are walking home from the subway/bus stop from work etc... and that'd be considered an every day use thing. What woman would want to permanently walk around with teeth in her vagina for a hypothetical situation? I know I wouldn't. I think I'd take my chances with out one. Thanks.