The essay confirms my suspicions about these social networks. When someone is "over-connected" the connections lose meaning; I think this is because most people instinctively know that someone just cannot have that many 'friends', not even 'acquaintances'. I believe this is not a hard limit, but there clearly is a limit.
If I had to answer honestly how many friends I have, I would say "a hand full at most". All the other people I get along with, I regularly chat with, I meet and work with, I go out with: they are not friends, whom I could call upon at any time for any reason and they would drop everything to hear me out. This might be a dramatic definition of friend, but keep in mind it is not set in stone; it is not easy to draw a line (because I don't really want to).
I like being online and having all my pals there. But seldomly it goes beyond that. Having said that, I do not want to push away anyone! Feelings or sympathies can change. However, I do not expect to become friends with everyone I get along with: There is a difference between trust (if not to say love) and getting along.
So, yeah, I do have a twitter account but it has been dormant since 2007; I used to be on myspace but the software they use is just a pile of crap; I closed my facebook account because I couldn't see the point of having to re-ignore people again who I had avoided in the past. On the other hand, I really enjoy donationcoder.com, but even here I do not know many people.