Naked Protests

It is quite common for protesters to take off their clothes to publicize a political injustice or social issue.  These students are promoting a workers' union.

Generally the nudity has nothing to do with the issue being publicized.  The nudity is meant only to draw viewer attention, and perhaps to emphasize the vulnerability of the protesters in the face of giant corporations or authoritarian governments.  Here, for instance, Tibetan students strip to their underwear to protest Chinese oppression.

The most famous naked protest is the Oblation Run at the University of the Philippines, named after Oblation, a statue of a naked man on campus.  Every December since 1977, members of the Alpha Phi Omega fraternity have taken off their clothes, put on masks to hide their identity, and run through the streets to promote a designated issue.

Since the protesters are university students, the themes are often educational: no tuition increase, wage increase for university employees, an end to fraternity violence.

Political themes are also common: free and clean elections, the ouster of President Joseph Estrada, an end to martial law on the island of Mindanao.

Fraternities at several University of the Philippines campuses participate, but the most frequent is Dilman, the main campus in Quezon City.

Politicians regularly condemn the Oblation Run as decadent, lewd, and immoral, but there is no law against public nudity in Quezon City, so there's not much that they can do.

Besides, you're supposed to be looking at the signs, not the physiques.