"Hey, we kept track of all the things you read here. This month you spent 13 hours looking at clickbait-boobies, 2 on politics and 27 on coverage of divorce cases. Wouldn't it suck if someone else used your machine right now or if we gave this information to tens of third-parties (we already did)?"

I would support that. Might make people more aware of how pervasive tracking is.