I'm no Facebook fan, but let's be honest. Your bank, credit card company, and merchants are all doing exactly the same thing. Perhaps the bank is regulated tightly enough that it isn't quite as bad, but the others definitely are.
Although IIRC Facebook already buys some of this info from data brokers so...
But they do ?
https://www.aclu.org/blog/privacy-technology/consumer-privac...
> In 1999, Congress passed the Gramm-Leach-Bliley Act (GLB).
...
> Under GLB, companies can sell their customers’ financial data to anyone they choose, including credit card information such as the date, amount, and recipient of charges, and the personal details consumers provide when they fill out applications. Consumers have no privacy under federal regulations unless they affirmatively take steps to “opt out” of this sharing, repeating the process for each and every financial service provider who may have data about them.
...
> Even this opt-out option is not available for consumers to stop credit card companies and issuing banks from sharing this data with their financial affiliates and financial “joint marketers,” a vaguely defined term that provides a giant loophole in privacy protections.
PS. Just to make sure - I'm not trying to defend Facebook here, or credit card companies.