Since before Netscape originally jumpstarted the Web user tracking and profiling surveillance industry, we already knew that one of the big categories of risk of such databases is being penalized for inaccurate information (and being unable to correct it, or even know it's there).
Think twice before you take a poo in your own profiles.
If you want to poison your profile without it backfiring on you, you might want to wait until pretty much all profiles are poisoned simultaneously.
The pervasive intimate surveillance is a grave matter. These profiles do and will affect you in many more ways. "Tt's about showing you ads that are relevant" has been an industry PR lie for a long time.
I agree that it is a grave matter which many people take far too lightly. But I also refuse to be scared by some junkie advertisers. And currently we at least are still talking about mainly pseudo-anonymous profiles. Filling this data with wrong info takes away most of the value.
Think twice before you take a poo in your own profiles.
If you want to poison your profile without it backfiring on you, you might want to wait until pretty much all profiles are poisoned simultaneously.