I only wonder what things have been like has a group of ten or twenty armed Jihadis had attacked rather than one dude. This happened in Mubai India. What if they captured the building? Or if they did this in a state government building? Let us be thankful the ISIS only has this to respond to our attacks.
The impact of having no real network, no solid connection, between the anti-social jihadist wannabees and ISIS make it a very effective method of inducing terror, which is what terrorism is all about. Best approach is to annihilate Islam right here in the US, starting with the jihadist training camps, and followed by a roundup of anyone who bitches about the first phase.