If black teenagers in Southeast DC are throwing stones at buses, endangering lives [1] and causing property damage, the obvious solution is a police campaign to arrest some them, and put them in jail, possibly with "exemplary sentencing" [2].
The DC government's alternative solution is pictured below: a poster asking them to stop.[See Don’t throw stones at glass houses—Residents of 97% Black Southeast Washington D.C. Warned About Throwing Rocks at Buses [3], by Paul Kersey, January 9, 2013]
This reminds me of the story that when Woody Allen was having a problem with pigeons [4]on his New York balcony, one thing he tried was a sign saying "No pigeons."
Links:
[1] http://www.vdare.com/articles/the-fulford-file-unarmed-black-teenagers-threat-menace-or-both-david-frum-doesn-t-seem-to-k
[2] http://www.vdare.com/articles/tinley-park-five-get-some-jail-but-where-is-doj-s-eric-my-people-holder
[3] http://stuffblackpeopledontlike.blogspot.com/2013/01/dont-throw-stones-at-glass-houses.html
[4] http://www.capitalnewyork.com/article/culture/2012/10/6538376/rats-wings-uneasy-deal-between-new-yorkers-and-our-pigeons?top-featured-1