This 'post-it' war between two office buildings is insane!

Pics 31/05/2016
Everything started with an innocent 'HI' on the 6th floor of an office building in NYC.
Soon a 'Sup?' turned up on an adjacent office building and thus a post-it conversation was born.
It eventually escalated into a war as you can see in the gallery above.
But nothing could prepare them for the epic post-it finale that won the war...