Protecting Trump in a second administration presents unprecedented security challenges [Video]

As Donald Trump conducts his transition from his Mar-a-Lago estate, drawing flocks of business moguls, contractors, foreign dignitaries and anyone looking for jobs in the new administration, the federal agencies charged with protecting the president-elect and his communications face a daunting task.Security at Mar-a-Lago has already ramped up since the election. The Secret Service has increased its footprint around the residence and private club, and now deploys robot dogs capable of surveillance and detecting explosive material. Meanwhile, the U.S. Coast Guard patrols the nearby waterways.But with no restrictions on who Mar-a-Lago club members can bring as guests, the chaotic scene presents a unique counterintelligence and security challenge that sources told CNN is almost impossible to fully prepare for.Trump enters his second term as president, facing an unprecedented combination of targeted cyber and physical threats. China has tried to hack the communications of Trump and his inner circle. Iran has allegedly …