As the world of communication continues to change, so does defamation. There are examples where an emoticon has been considered sufficiently serious to be defamatory.
In the English case of Lord McAlpine v Sally Bercow, there was a tweet containing the 'innocent face' emoticon. The court concluded "the reasonable reader would understand the words' innocent face' to be insincere and ironical".
Emoticons have a tag or title worldwide so that they can be translated into words and meaning. However, defamation is contextual, so there could be plenty of other scenarios where this emoticon would not be considered defamatory.