It was October last year and the US Department of Homeland Security's social media team had shifted into overdrive. Among a flurry of new videos, each more nationalistic than the last, one stood out. A grainy montage depicting an American golden age is spliced with scenes of patriotism, consumerism and military might. An American flag is planted on the moon. Fighter jets fly in formation. And a spritely Donald Trump strides through New York City. Overlaid are the words "LIFE AFTER ALL CRIMINAL ALIENS ARE DEPORTED". But buried in the 50 second video is a clip with far more sinister...