Email can't be defined as a Social Network in the context of this patent, because they had to define what it constitutes a Social Network to be able to use the term in their text.
But Windows Live Messenger can be defined as a SN, with that definition. I don't know if Yahoo! Messenger could also be included, because I don't use it and I'm not very familiar with it.
I would certainly hope that any IP attorney litigating these patents would be able to argue that email is most definitely not a social network as used in the context of the patent.
