Police at the University of Michigan warned female students taking part in this week's Naked Mile run that they ran the risk of their pictures appearing on the Internet. The annual midnight nude race across the campus marks the end of the spring semester, and police say 1,000 runners, including 250 female students, took part last year. But following the race, videos of the women, taken by some of the 10,000 spectators, appeared on the Internet, where they are still on sale.

The police also warned women of the risk of sexual assault from spectators, and warned all participants they could be arrested for indecent exposure. However, the university police chief acknowledged the popularity of the 12-year-old run, and said his main concern was to protect the students.