While it seems limitless, Sean Silverthorne interviews Benjamin G. Edelman about the current problems with IP addresses and their almost exhausted supply under IPv4 in a recent
HBS Working Knowledge piece on Research and Knowledge titled
When the Internet Runs Out of IP Addresses While the future move to IPv6 will add trillions of new addresses, the road from here to there may be a bumpy one.
I found it an interesting interview and it touched on a problem that I had never thought of before.