Party crashers managed to sneak into the White House dinner and get their picture taken with some high ranking Obama officials. 'They were not armed' does not really matter. That is, unless you assume that there were no knifes at the tables for dinner. It also assumes incorrectly that people are not capable of doing serious damage with their hands, and quickly at that. Obama appears to never have been in any danger, nor was anyone else, but if pranksters can manipulate their way into these events so can more nefarious people.
Video embedded below.