I am on a side which sometimes offend, mostly in non-technical details. As you don't see/hear a person, you can't adjust your expressions in real-time (and add some non-verbal layer as well). Then out of the blue your peer becomes offended by something you even did not mean - with chats/e-mails people often add missing nuances of the communication. And that extra layer is combination of their current mood, some believe or disbelieve in people, and your imagination about you.

Sometimes generated confusion is too unexpected and painful for both, so I prefer to limit online discussions to work stuff.