Umbrella for Urban Combat
Around Harvard you can tell the MBAs in the rain because they're the ones with the giant umbrellas. Those are are nice about it raise their umbrella and generally play well with others on the sidewalk. The jerks are the ones who barge through the city hitting the umbrellas of others at will.
It's because of them that I've invented the Urban Combat Umbrella which lets you exact virtual revenge by putting them in your sights and making shooting noises until you heart's content.