I think that, sometimes, problems arise because a poster says something tongue in cheek, but because we can't see their facial expression the text is taken literally and certain readers misconstrue the message and take offence. I've often typed something and then thought better of it before I post it for that very reason! Even putting a
after the post to indicate that it was meant in a jokey way sometimes fails to work.
Guilt at feelings of resentment
Police launch an investigation into Ann Widdecombe death
What words annoy you when used wrong or people don't know the meaning of?

