The Transportation Security Administration issued an advisory on Friday that a Piper PA 25 Pawnee crop-dusting aircraft was stolen from Ejido Queretaro, near Mexicali, Mexico, on Nov. 1. "Although there is currently no indication that this has any connection to terrorist activity," the TSA said, "the theft is cause for concern. Past information indicates that members of al-Qa'ida may have planned -- or may still be planning -- to disperse biological or chemical agents from cropdusting aircraft." The stolen aircraft is registered in Mexico and bears the tail number XBCYP. If you see the aircraft, the TSA says you...