The entire problem is that we can't stop someone (namely Mr. Mosquito) from coming up to us with a needle full of something and stabbing us with it (that they already stabbed other people with) without our consent.
I'd much prefer we got rid of Mr. Mosquito, but if we won't (or can't) we can at least make sure that what's in that jerk's needle stops killing people every day.
I'd much prefer we got rid of Mr. Mosquito, but if we won't (or can't) we can at least make sure that what's in that jerk's needle stops killing people every day.