Mexico City ? Actor Sean Penn said he has "nothin' to hide," after images published Monday indicated he was under surveillance when he met with the Mexican actress who led him to Joaquin "El Chapo" Guzman ? and the pair was apparently followed and photographed as they set out for the supposedly secret meeting with the drug lord. In a brief email exchange with The Associated Press, Penn also dismissed criticism over his interview with the fugitive, who was captured on Friday, a day before Penn's 10,000-word story was published in Rolling Stone magazine.