By Holmes Lybrand, CNN HUNTSVILLE, AL (CNN) — On Thursday, the first whistle blew, ushering in the largest sporting event the US has ever hosted — or secured. Millions of foreign fans are expected to descend across the country for the World Cup, with the US hosting 78 matches across 11 cities and countless more fan hubs and related events peppered throughout the country. The scale alone presents a challenge for local and federal law enforcement …