Approximately 65% of our communication is non-verbal/body language. 25% is the tone of voice we use when we say things and the remaining 10% is the actual words that we use. Because of this, online communication is currently limited to the 10% of communication that we are able to express with a keyboard. The possibility of wrongful interpretation is magnified because the mind fills in gaps that we don't get from body and tone. This has been helped slightly by the use of smiles to express a part of body language that the internet otherwise lacks. However, all too often our words are taken offensively when no offense was intended.
Frenchman: "I'm sweatin' like a U.S. politian in church... N.O.I.!"