Not daft at all, Gemini789, it's a question worth thinking about, even if just as individuals! I often wonder if people on social media and news posts would be just as rude and nasty to someone face-to-face. I'm pretty sure some would and others would shrivel under the harsh light. On Gransnet, most posters come across as quite genuine, if a bit "more so" at times.
I'm guessing some let their "telling it like it is" (to them) tendency rule while maybe others are just having a bad day, are triggered by the topic, etc. I've read posts on here that I thought were pretty hurtful and then noticed that same poster be very compassionate and kind on a different thread so who knows, right?