New Yorkers try to stick-it to their neighbors on one Manhattan block in a so-called post-it note war.
Advertising agencies Havas Worldwide and Horizon Media are dueling via some fun imagery in TriBeCa.
Colorful pictures, made entirely of post-it notes, line windows of the two buildings on Canal Street near Varick Street.
Participants say the back and forth first broke out last week through social media and is all in good fun.
"We saw that Getty had put up some really cool Mario Brothers and we were like 'Oh, my god we're in trouble. We have to get a little more creative,'" said Tasha Hanna, who works for Havas Worldwide. "And my co-worker did the Batman symbol and that's when it really started kicking into gear."
"I didn't realize how big of an advertising area this was, though, and how many more advertising firms were in the building across the street," Hanna said. "So it seems like some of us kind of knew each other. It was a bit of a conversation."
For those looking to see more of the images, look for the trending hashtags "Canal Notes" and "Post it War."