Greenpeace activists protest against the contamination of Mexico's maize supply from genetically engineered (GE) maize. Greenpeace and professional crop circle makers from the UK created a 65m. "crop circle" question mark in a maize field in Ayotzintepec, Oaxaca, a region that has been contaminated by GE maize. The question mark signifies the unknown nature of where genetic contamination can occur.
© Greenpeace / Gustavo Graf