FB is a minefield, My Missus has gotten herself in trouble recently with our eldest’s school over the most benign of FB posts (actually other people’s misinterpretation and stupid responses)…
Most organisations are now very conscious of how their employees conduct themselves on FB or Twitter can be seen as a reflection of the organisation as a whole…
My employers seem to have recently lifted the block on FB, but there’s no way I’ll be using it from a work computer.
IMO, use FB to keep in touch with people, share the odd photo with friends or family maybe but Do not post opinions or say anything negative about anybody, you simply don’t know which “Friend of a Friend” will share what you write with others, or how people may interpret / misunderstand what you write…
Nobody of any importance ever looks at STW so you can write what you like on here and you’ll be golden…
I’d expect a moderate bollocking if I were you OP, but dismissal would be unlikely I’d have thought, and would probably not stand up at a tribunal…