Citizen: at our city's airport, we have invested time and money in security checkpoints that are a waste of time. We train and staff security staff for the purpose of searching incoming automobiles, but we search fewer than five percent of those automobiles. We might as well disband the security checkpoints. The cost is wasted, and there is a ninety-five percent chance that an illegal substance would get through the checkpoint anyway.
Council member: Even if we granted that those odds didn't justify the costs--which I disagree with--you seem not to recognize that the presence of the checkpoint itself deters some people who would bring in illegal substances from doing so.
The council member