I don't think it's the advertisement itself, I believe it's the method and data they collected to target it. They may not use it for nefarious reasons (one can

I don't think it's the advertisement itself, I believe it's the method and data they collected to target it. They may not use it for nefarious reasons (one can argue if unwanted targeted ads is or isn't) but that data may leak either directly or via a 3rd party who purchased it. Then you have a situation where you have all this product and personal history which could be embarrassing and be used for blackmail. Can you delete this data? Do you know everything they are tracking? Someone else said it best, this is a cyber stalking industry.