What this person mentions is really just the tip of the iceberg. They link credit cards to phones because GPS coordinates and WiFi networks nail down your address, which they cross-reference with the billing address of credit cards.

They know who are you sleeping with, or if you aren't sleeping with anyone. They know your age and all the insecurities you have about your body, not to mention your health problems and every embarrassing fact about you. They know where you've been, where you're planning on going, and your political preferences. They know if you've donated to political parties, attended political rallies, if you voted, where, and when. And they know all your friends.

And we just let them do this. As tech people, we built this. And all the along the way we told ourselves it was fine, because it was very lucrative for the entire ad tech/fintech/startup ecosystem, and us personally.