I didn’t use a Bruner phone for about 15 years and only found out about the FB connection when I received a friend request off a regular SP I saw a lot
I asked how she found me and she said she just searched my phone number on FB!
I’ve removed my number from my FB settings now so that wouldn’t happen again (and I have a burner phone now too)
And for those wondering, yes I did accept the friend request and we remain friends to this day
she’s sadly retired now but we were really good friends for a while