Google leads the way among ad tech companies sharing your online behavior and location with advertisers. It happens an average of 747 times a day in the United States and 376 times a day in Europe. That’s according to a new report from a civil liberties group.

Google and others use a process known as real-time bidding to help advertisers target you by behavior and location.

The group behind the report called such sharing “the biggest data breach” in the world.