Every year in early July, two days before the Running of the Bulls and the festival San Fermin in Pamplona, Spain, a group of PETA activists stages a protest against animal cruelty. They move along the route of the bull run from the corrals of Santo Domingo to Plaza de Toros, often splashed with red paint resembling blood and wearing only plastic horns. This stampede of naked people cannot go unnoticed, drawing attention to the cruelty of bullfighting.
This nude run tradition began in 2002 when some 25 animal rights activists ran undressed through the streets of Pamplona to promote a less violent and sort of sexier alternative to the infamous blood tradition. Local residents, initially terrified by the naked action, have softened a bit towards the somewhat awkward twist in traditional festivities. Besides the moral standpoint, some locals are inspired by an extra economic boost for the townspeople, as otherwise, those activists would normally never think of attending such a bloody festival.
Animal rights groups across Europe and North America have promoted the event and do their best to assist participant runners in transportation and accommodation costs. Each year, the activists stage a different performance to draw attention to the death of over 50 bulls annually. Location may differ, so you might want to check with the organizers for more details.