[A_COMPUTER]

I suspect the problem would be like when Microsoft was making Comic Chat (a visual, comic-strip-based chat client) and their users were flooding IRC channels with useless metadata that normal clients didn't know how to filter out. I feel like this as a transitional period would be worth it though, and not significantly more painful than right now clients dealing with ical/outlook event notifications. I am really surprised nobody's made even a toy implementation of a social network on top of SMTP.