Even with an invitation to the White House, it can be tricky to get through the heavily guarded perimeter. So the revelation that a couple of aspiring socialites were able to talk their way into the state reception for India's prime minister last week, left officials scrambling for answers. President Obama, who met the couple in a receiving line, was said to be angry about the incident and received a public apology from the Secret Service, which said procedures hadn't been followed at an entry point. But now the White House deputy chief of staff, Jim Messina, has issued a memo instructing members of his team to be stationed alongside secret service agents at entry check-points, for all White House events. Their role will be to cross-reference the guest list as people arrive. The White House has declined a request to send the Obama social secretary to the forthcoming Congressional hearing on the matter. It's unclear whether the couple who sparked this furore, Tareq and Michaele Salahi, will be attending, although this time they do have an invitation.