On Lantau island, the largest in Hong Kong, cattle and water buffalo were once used to plow rice paddies. With the decline of rural life in the 1970s, the cattle were set free and now wander the island grazing in herds. Many people find them picturesque, an endearing part of the Lantau experience. Others, though, want them gone, claiming the seemingly placid beasts destroy fences, eat crops, block traffic on local roads, and even attack people. Last year, for instance, a young water buffalo charged and gored a tourist, severely injuring him.