I've been on several in the last few years (neighborhood watch, residents association etc) but always ended up leaving them because, after a few months of everyone communicating politely and helpfully, invariably one or two smartarses come along making rude, patronising remarks; or sneering at someone's posts; or just very obviously trying to pick fights with people. The whole tone of the chat group then becomes tense and unpleasant, the sensible and polite people stop posting and it just descends into bickering and arguing.
AIBU to wonder why some people cannot seem to engage on any kind of online type group without becoming rude and argumentative?