How about no free stuff on the web? Charge for services and make it illegal to sell private information without the subject’s consent and remuneration.
The genie is out of the bottle at this point. IMHO the only method forward is how do we as a society responsibly allow for coexistence such that all parties are satisfied.
> Making it illegal won't solve much. E.g. FB doesn't sell private information, they sell the ability to target demographics.
You just need to appropriately specify what's being made illegal. You're right that FB could weasel out of a law that outlawed selling private information. They couldn't weasel out of a law that outlawed monetizing personal data without user consent.
Make their only defense be cooperation in prosecuting the offending party.