THE grand golden doors of 500 Pearl Street, in Manhattan, have welcomed such glamorous names as Hermès, Tiffany & Co and Kering, a French conglomerate whose treasures include Gucci and Bottega Veneta. The building is not a posh hotel or department store. It is the federal court for the Southern District of New York, a favoured battleground for the decidedly unglamorous war against counterfeit goods. The court is now the venue for Kering’s suit against Alibaba, a Chinese e-commerce giant.