Residents of one Michigan city are pulling out all the stops to catch a serial pooper who has been despoiling their playground slides. Ypsilanti locals have started a hashtag and even put up a billboard in an attempt to bring the fecal fiend to justice.

The mystery pooper has been on the loose for six months, with police even installing a hidden camera in an effort to catch him.

Local ad company Adams Outdoor Advertising did its part by having an in-house designer whip up a billboard with a rotating series of messages asking citizens to report the pooper via Twitter hashtag.

"Our art guy had a lot of fun," Adams general manager Todd McWilliams told the Daily Dot. "He came up with a few designs—and I rejected a few."

The three taglines read, "Do your civic doody, report the pooper," "Help us flush the pooper," and "Help us catch the poopetrator."

City officials aren't exactly grateful for the help, even though they've failed for half a year to catch a guy who shits on playgrounds.

"We're not authorizing it and we don't need it," City Manager Ralph Lange told Mlive.

Within a day of the billboard going up up, Lange said police were "closing in" on a person of interest in the case.

[Photo: Twitter]