I recently spoke with an engineer who was building a product using the information he is able to acquire from these data brokers. This includes every search query you've ever made, anything you've purchased with a credit card, and anything that is in the public record (i.e. a pending divorce case, or child custody dispute). He uses that information to generate a profile on leads to determine how much they can squeeze from this person in whatever deal they are making. (I'm not going to get more specific than that.) This person had no incentive to lie to me about what they were building.

The data trail you are creating is much more personal and invasive than you want to imagine, and in the wrong hands it could be used to devastating effect.

Every search query you’ve ever made is not available from any data broker and if you hear otherwise someone is lying