Anyway, what goes around comes around.
There is always the chance that you might say something that the other party thinks of as insulting but then its an easy thing to apologise and say that you didnt mean no offence by it. Instead of hiding behind the fact that you used a smily. Cos if everything thats been said followed by a smily has to be taken lightly then i can start randomly insulting ppl wherever i go and just guess they wont take it serious since i used a

for example: we all know moley (sorry sweetie for using you), he's the biggest spammer around and doesnt really watch what he's saying. If he calls me a bitch and i call him a twat we both know that its for a laugh. But other ppl that dont know the situation or me and moley wont see it like that.
At the end it all comes down to respect. And to treat other ppl like we want to be treated ourselves.