What does this mean? Absolutely nothing if you do not use Gaim, the multi-protocol, cross-platform, open source Instant Messenging client. The OSCAR protocol drives the AOL Instant Messenger network.
Check out the screenshot to the right. While "Send File" works fine some of the time, receiving files from other AIM users who are not using Gaim fails. I do not often transfer files through AIM (partly because Gaim is so bad at it), but the majority of my transfers do occur on the same subnet (a subnet is a subdivision of a larger Internet network; subnets have similar IP addresses, last year at Harvard, many other Dunster residents and I made up the 140.247.159.* subnet), so I am somewhat psyched.