Ars Techinca has been following an interesting issue being raised by several members of Congress: Should companies such as Apple, Google and Research In Motion stop selling or otherwise making available smartphone apps that help drunk drivers avoid DUI checkpoints? An open letter from U.S. Senators Frank Lautenberg, Harry Reid, Charles Schumer and Tom Udall sent to these companies back in March asserted that such software is “harmful to public safety” and should not be offered. RIM quickly agreed to the senators’ request, but two months later Apple is still pondering the issue. Apple’s Catherine Novelli stated that there are differences of opinion on whether flagging the locations of checkpoints is inherently good or bad, Ars reports. “We are reviewing the situation and determining the best course of action in a thoughtful manner,” she said. At a Senate hearing Thursday on mobile privacy issues, Sen. Udall used his allotted five minutes to raise the issue once again, and to put the heat on Apple and Google for not removing DUI checkpoint apps such as DUI Dodger, Buzzed, Checkpoint Wingman and PhantomALERT from their stores. Udall contends that that the apps encourage users to break the law. Apple’s Novelli notes, however,…