I don't want to sound like a fan boy or anything but I can't recall a time when Xbox live was down for more than a few hours.
The complaint describes the December outages -- chronicled on blogs and elsewhere -- that kept people from "accessing online play for several weeks. ... Xbox Live continues to deny subscribers access and has even issued apologies for their failure to correct server problems."
Here is the suit if you want to read it and do more research (PDF):
http://blog.seattlepi.com/microsoft/files/library/xboxlive01...