Loose lips kill SEALs, and the American government is afraid politicians will lead terrorists to the guys who killed Osama bin Laden. The U.S. had planned for all aspects of the raid on bin laden's Pakistani hideout on May 2nd. This included an agreement that details of the raid would be kept from the media. That failed with 24 hours, as politicians eager to revel in the attention the success this raid produced, released all sorts of stuff. Not the names of the shooters. But, it is feared, as more details come tumbling out of the loose lips of politicians and their staffs, this will lead to the names of the SEALs who did the deed. Those SEALs are not so much concerned with themselves, as they are with their wives and children. The fears are real. In Britain, with a larger number of Islamic terrorists, and al Qaeda supporters, there were several incidents of these terrorists getting the names of British military personnel, tracking down their families, and making threats.
There has been less of this in the United States, and that's the reason why U.S. troops in combat zones don't give their full names. Members of the special operations community (Special Forces, SEALs and so on), do not even like to have their pictures taken. There's concern that eager journalists, or politicians, will name the shooters and make them, and their families, targets for vengeance.