pollution on a stick
n. A pejorative name for billboards, particularly as used by environmentalists and anti-corporate activists.
Although reviled by some as "pollution on a stick", billboards have become one of the hottest advertising media.
—John Heinzl, “Billboards enjoy boom times,” The Globe and Mail (Canada), June 16, 1999
Kelley worries about some of the fights he has lost. He predicts that gambling will increase crime in the state. He growls about his lack of success in eliminating billboards, a cause he has championed since the 1970s.

"They're just pollution on a stick. You don't need them at all," he said.
—Dee-Ann Durbin, “Kelley stepping down after 37 years and five governors,” The Associated Press, December 26, 1998
1991 (earliest)
But name another medium so dogged by regulators. Environmentalists call billboards "pollution on a stick." Six states and more than a thousand local governments, including cities such as Houston, St. Louis and San Diego, have restricted them.
—Adam Snyder, “Billboards' shadow growing,” Chicago Tribune, July 14, 1991