found -- mixed in with the protesters. this was the first big security challenge after the attacks in london please were facing a double threat the ongoing threat of a terrorist attack plus there's real fear that anarchist protesters would cause a lot of damage. julie: amy kellogg thank you. the cherry blossoms are blooming and hundreds of thousands of people are heading to the nations capital to ♪ ♪ ♪ ♪ ♪ sfx: engine revving ♪ (silence) ♪