zoo-bombing
n.— «A daring Portland ritual sent one woman to the hospital earlier this week and brought attention to a fad often referred to as “zoo bombing.” Zoo bombing is when cyclists barrel down a hill as fast as they can, like the hill below the Oregon Zoo, or—even more risky—the highway that runs from the zoo to the edge of downtown Portland.» —“Portland ‘zoo bombing’ ritual gets more risky” by Teresa Bell KGW-TV (Portland, Oregon) June 6, 2006. (source: Double-Tongued Dictionary)