It bothers me when random people put xs after their name at the end of emails to me. I've had several people whom I've never met in person do this in the last few weeks, along with a few who I've only met once or twice.
Don't get me wrong - I often sign off "xxx", but only when I'm writing to someone whom I'd actually kiss goodbye if I saw them in person. I think it cheapens our gestures of love and affection when we use them with everyone. I think technology can give us a false sense of intimacy; we deceive ourselves that our lives are full of love and fluffiness, when we are actually increasingly isolated and lonely... (must get off this computer now and have a real conversation with someone!)