Sens. Chuck Schumer (D-N.Y.), Harry Reid (D-Nev.), Tom Udall (D-N.M.), and Frank Lautenberg (D-N.J.) are offended by smart phone apps that help drivers locate DUI checkpoints. In March the quartet wrote to the smart phone makers at Apple, Google, and Research in Motion (which manufactures Blackberries) to tell them so.

The senators argued that “providing access to applications that alert users to DUI checkpoints is harmful to public safety.” The letter did not discuss app users who know that such checkpoints are usually accompanied by roving cops on their perimeter and who thus decide not to drink and drive at all. Nor did it address the convenience of drivers who have not been drinking but would prefer to avoid delays.

Research in Motion caved instantly to the extralegal pressure, removing two apps, PhantomALERT and Trapster, from its official store. The producers of both applications reported increased sales following the media attention generated by the senators’ letter. Apple and Google did not give in, and many more such apps are available, including Buzzed, Checkpoint Wingman, and Mr. DUI.