In some states driving records are public info. Also you are conflating government records with corporate info. We have different laws regulating both. By in large corporate data privacy outside of fair credit reporting law is non existent. And where the law has teeth nothing has happened (e.g Experian)... really the issue for Facebook is the political foreign influence on elections. Politicians really don’t like it when they have no control over their electorate.
This is an argument you have to make, but you're just asserting it. If I get pulled over for speeding, I have to show my driver's license, which I also used to open my bank account, which I use to pay my phone bill, which I use to call my mother on her phone, which she pays for out of her bank account, which she used her driver's license to open, which she had to show to get past the security desk at a building downtown to go to a job interview with a business that rents a space there.
Are you saying that I should expect that interviewer to have access to my driving record? If not, to what degree should it be "fairly clear" to me that there is information shared, and why?
OK, now pretend that I used facebook login to periodically read articles about selling fishing gear, at the website for a membership trade organization for fishing gear merchants that I belong to. I set it up (with two clicks) because I was sick of typing my membership number in on the rare occasion I visit the site. It's like 12 digits, and it's like not I keep my membership card in my wallet; I only need it for conventions...