Peru’s Nazca lines, massive etchings of figures in the desert, have a history that dates back 2,000 years. This week, that history may have been changed for the next thousand when Greenpeace protesters failed to wear the right shoes to a demonstration.

In quite possibly the biggest faux pas of the week, Greenpeace activists treaded on the land surrounding Peru’s Nazca lines as they laid out yellow cloth letters to catch the attention of global leaders attending U.N. climate talks in Lima. The message was, “Time for Change; The Future is Renewable.”

The South American and European demonstrators also caught the attention of the country’s government, which promptly decided to charge them with, “attacking archeological monuments,” which is punishable by six years in prison. Deputy Culture Minister Luis Jaime Castillo told the Associated Press that he worried the Greenpeace activists’ footprints would last for hundreds, if not thousands of years. No one, he said, is allowed on that sacred ground, unless they get special permission and wear special shoes.

So much for not leaving a damaging mark on the Earth.