It’s a pretty big firm, so when I joined it, I was aware that some of my FB friends (old school or uni pals, or people I just knew) worked there. I wasn’t exactly going to unfriend them!
In my old firm I had two of my closest work friends on FB but that was it. I’ve now got more from the old place now that I don’t work there any more.
Back in the day when I was afraid of someone tagging me dancing on Mojos’ bar at 3am on a Tuesday, I was properly para about having workmates on there. But now any 3am postings on a tuesday are me complaining about toddlers who don’t sleep, and far lass likely to have me sacked.