I keep a (deactivated) Facebook account just to prevent Facebook leaking my acquaintances to any random with my name and email.

That's right - in 2021, Facebook doesn't make you immediately verify your email when you sign up! They eventually close the account if you don't verify but by that point whoever signed up with your name and email already has access to parts of your shadow profile Facebook leaks (ex through 'suggested friends').

cool. i have some experimenting to do in my name now.

I go through this frequently and it's not even due to Facebook, it's just due to having a stupidly common western name.

To the point of I have folders, digital and physical full of sworn statements I've had to make, and official court documents from six different states attesting "no the John Doe before you applying for this job is not the one who came up in your background check database for grand larceny, no he's not the one who came up for involuntary manslaughter either." and I'm always ready for that conversation later in the interview when I get an email from the recruiter/HR "hey, we have a question about something that came up in your background check"

This can cause a problem when dating as background checks become involved. Thankfully my SO realized it was a different person with the same name.

Even at a small town library there was another patron with my name.

You realize by making an account and adding a picture you greatly increase the chance someone will clone your profile vs someone creating a profile with photos they have sourced from somewhere else. If the latter happens it is probably from your friend group.

Who said I had a picture of myself? I can post something proving it's me as necessary, which is what I use it for. Zero personal pictures, though.

Just keep the profile private and limit friends on FB. I try to keep the number of FB friends at Dunbars number.

You would need to have a very unique name for that to be necessary and you are also putting a lot of confidence in HR's ability to disambiguate the profiles if you indeed have a doppelganger.

On the contrary, I have an exceedingly common name, which is why I need to have my own account to point to, as compared to the other several dozen same-name folks who have the potential to cause me trouble. There's no trusting HR here, it's a matter of being ready up front.

Why not just tell HR that you don't have an account because you don't want people confusing you with another person?

Perfectly reasonable question. The answer is that it has been my experience (across multiple companies, over significant time) that they tend to think you're making excuses for not showing your real profile unless you have an actual profile to show them.