The Secret Service had a total breakdown in security, and whether one likes President Obama or not, I think this is cause for concern when uninvited guests can get into this type of event, and meet the President. Especially considering he was hosting a foreign dignitary, and these 2 individuals could well have had intentions of harming either President Obama or Prime Minister Singh. I do not think it would be positive for the United States if the PM of another country was physically harmed at a White House dinner due to errors on the part of the US Secret Service, let alone if harm were done to the US President.
Gate Crashers Met Obama At State Dinner With India
http://www.nytimes.com/reuters/2009/11/27/news/news-us-obama-dinner-security.html