At least one good thing came out of the massive Sony Pictures hack — a big raise for Charlize Theron. It’s the latest proof that transparency can level the playing field for women seeking equal pay for equal work.

Theron, an Oscar-winning actress, reportedly used the hack against Sony late last year to negotiate a deal worth more than $10 million in order to get paid the same as her male co-star, Chris Hemsworth, for their upcoming film “The Huntsman.” Though the hack revealed nothing about her or Hemsworth’s pay for the movie, it did show how women in Hollywood often earn less than their male counterparts, reportedly inspiring Theron to demand equal pay.

This is a prominent example of something lawmakers, experts and advocates have been saying for years: When women know how much their co-workers are getting paid, they’re more likely to be paid fairly.

“It’s a very basic check on discrimination,” said Ariane Hegewisch, the study director at the Institute for Women’s Policy Research, a Washington-based think tank. “If you don’t know whether you’re paid equally you can’t enforce your right.”