As the smoke settles from the first week of legal marijuana sales in Colorado, experts are warning that sanctioned pot dealers could become targets for the very folks they put out of business. Taking over a trade once ruled by drug cartels and turning it into an all-cash business could make pot shops prime targets for extortion, black-market competition and robbery. One veteran border narcotics agent told FoxNews.com Colorado's legal pot industry will find it hard to keep the criminals from horning in on a lucrative business they once controlled. "Mexico is already in Colorado without the risks," the agent,...