Robert McCartney, in his Aug. 1 Metro column, “Why bars in Md. should be liable for drunk patrons,” arguing that Maryland should abandon the traditional common-law rule by which restaurants are mostly not responsible for the later actions of patrons says a Gaithersburg craft brewery should have to pay for a customer’s crash even though its staff cut him off from further drinks and offered to get him a cab. Mr. McCartney sympathetically quoted a member of the victim’s family suggesting the restaurant should have insisted that he hand over his car keys.

Has he considered whether restaurants actually have a legal right to demand customers’ car keys, or what sorts of liability they might face if their staff were to begin snatching keys from patrons’ hands or blocking them from leaving? If the idea is instead that staff should be under an obligation to call the police if they suspect a customer of being impaired, better to pass a law laying out such a responsibility in clear language than to create open-ended rights to sue over unspecified negligence.

Mr. McCartney complained that a stalled bill to expand liability is opposed by influential lobbies in Annapolis such as the hospitality trade. He did not mention that injury lawyers pushing for the change are among the most influential lobbyists in their own right.

Walter Olson, Washington

The writer is a senior fellow at the Cato Institute.