"Maybe because it's hard for them to move their existing servers to AWS, because of IP address conflicts," someone else said. Sidebar: You can find your local IP address using `ipconfig getifaddr en1` (works for Macs for wireless internet connections). Maybe you're wondering, "why can't we just change the IP addresses so all machines have a unique IP address?" We've talked about why AWS needed VPCs, and the idea behind VPCs, but how are they implemented? A reader provided me with some extra context on AWS VPCs.