Tareq and Michaele Salahi, the party crashers that showed up to U.S. President Barack Obama's first stated dinner uninvited, was not the first such security breach. Two weeks prior to that incident, a Georgia couple, Harvey and Paula Darden, showed up to the White House a day early for a standard tour that is open to the public, only for the Secret Service to usher them into a private room for breakfast with President Obama. They too were able to shake his hand. Mr. Darden is a veteran. 

These security lapses are not good. The first two known incidents did not result in tragedy, but this pattern cannot continue, as it is compounded by the fact, the incumbent is the most targeted President in American history. It is simply not sound judgment and extremely dangerous.

Uninvited tourists' surprise breakfast with Barack and Michelle Obama

Wednesday 16 December 2009 13.20 GMT - When Harvey and Paula Darden, an Obama-supporting couple from Georgia, turned up at 1600 Pennsylvania Avenue last month, they were expecting a quick nose around the White House as part of a tour organised by their congressman...

"The further we got into the White House, the more surprised we were," said Darden. "My wife looked at me, and I looked at her, and I said, 'You know, I don't know if we're in the right place.'" He said he felt "kind of funny" after finding himself in the middle of a formal event with 200 others: "I was the only man in the room that wasn't dressed in a coat and tie," he said. "I was just a plain tourist."...

http://www.guardian.co.uk