Then, last summer, they started arriving by bus and by van, including one with an ominous black pirate flag: hundreds of young partyers from parts unknown, hauling kegs and cases of beer with them, guzzling it down fraternity style and, in a couple of cases immortalized in police summonses, relieving themselves in the dunes. The local newspaper, The East Hampton Star, called it The Invasion of the Beery Beach Blanketeers.