Barack Obama's campaign team, celebrated in political technology circles for its online innovations, took a high-tech jab at John McCain earlier this month with an ad that blasted the Republican presidential candidate over his limited computer use. The ad quickly backfired thanks to some basic Internet sleuthing that showed McCain rarely uses a computer or e-mail because of the bodily injuries he suffered while in a Vietnam War prison for five years. Now Obama's ad is the subject of counterattack. A group called Citizens for Open and Responsive Government created an ad that scolds Obama for his cheapshot. The ad notes that even Obama's running mate, Joe Biden, called the ad "terrible" in an interview with CBS' Katie Couric. The new ad features retired Army Lt. Col. Mike Fairhead, who also can't use a computer because of war injuries. "Mr. Obama, why do you attack Sen. McCain because of his disability?" Fairhead asks in the ad. -- K. Daniel Glover