Retail giants have a target on their backs. Hackers are picking them apart at a rate rarely seen in other industries. Louis Vuitton and Dior are part of a growing number of household names affected. Their breaches alone may have cost them upwards of $25 million. Moreover, Google has warned that the hacker group that cost British retailer M&S $400 million in a data breach is headed stateside.   For as long as the retail sector remains reactive, rather than proactive, the target on its back will