Yes, this XKCD comic came out in February of last year, but I still find it amusing (click on the image to see a larger version):
For those not following IPv6, the joke here is that the nanobot swarm (ex. grey goo) wound up having to stop their proliferation – and destruction of earth – because they ran out of IPv6 addresses! This was, of course, mathematically debated in an XKCD forum along with other discussion.
Thankfully, since we haven’t yet made the full migration to IPv6, we’re nowhere near needing to worry about their exhaustion!
P.S. Speaking of IPv6, are you ready for World IPv6 Launch on June 6?