An ad fraud operation called Hydra is skimming an estimated $130 million from advertisers, and Google and others are trying to stop it

· A new ad fraud scheme called Hydra is stealing millions from advertisers by impersonating app traffic, fraud watchers said.
· The operation was detected a year ago by Israeli company Protected Media, which recently brought it to the US ad industry's attention.
· "Operation Slay Hydra" is underway to stop it, but experts...