Ask HN: Facebook adding/accepting friends without me knowing?

I've logged into Facebook, and I saw a new message "You are now connected with John Doe". I clicked on John Doe thinking maybe I sent friend request some time ago. Nope. I never even seen this profile. So I asked the person if he accepted/added me. Nope, he has no idea either. The message was sent 30minutes ago so I am sure he/I would remember.

Did some investigation and it turns out the person is in my distant family - all mutual friends are family.

Being web developer myself I do not believe I fell for phishing attempt (even tho it's possible), and in that case, why would phisher add a random distant family member and no one else?

It's not the first time, but last time I thought I was phished so I changed my password and it was also slightly different. I noticed a person or two on my friend list I never heard of.

I feel this is the final straw. Got to think how I am going to move away from the platform, any tips? Seriously that's insane, wasn't the whole point of facebook at the beginning that you add who you want?