... and which they are supposed to provide upon request.
That being said, a less nefarious use could be lender has a std mortgage rate of 4.25%, but if you give us a FB data dump, you can quality for a 4.00% rate.
Or, with your FB, the bank realize you have an higher risk of defaulting/dying before paying the full mortgage, so they bump the rate to 5%
... Which is what this tool does.
And while I take your point about aggregate value, I personally have a great deal of interest in data about me.