Golden Gate Park Vandalism

First it was trees, now it's rose bushes. This is sad, and I don't understand how anyone can enjoy this. The amount of open space people can enjoy in San Francisco is scarce, and to vandal like this is ridiculous. How can San Francisco stop or prevent this crime against Environment?

http://abclocal.go.com/kgo/story?section=news/local/san_francisco&id=7622381