Completely ridiculous article, simple because of the fact that even though IP addresses are "Internet Protocol addresses", they don't have to be used for the Internet (there are these things called military, government and corporate networks). Next to that the Internet does not only consist of Akamai. Another fun factor you are forgetting about is this little thing called NAT, which, if one could take it into account would most likely (according to some other mysterious ways of calculation and big wet thumbs) means that the IPv4 address space was depleted already several times.