SKIDROW claimed their crack removed the DRM checks entirely rather than just emulating a server. The Message:
In early 2010, Ubisoft introduced a controversial DRM system for the PC version of Assassin’s Creed II The Christian Science Monitor Constant Connection: Assassins Creed 2 NoDVD 1.01 SKIDROW FIX AUTO
This system was widely criticized as "draconian," especially after a DDoS attack on Ubisoft's servers left legitimate buyers unable to play their games for hours. The Christian Science Monitor The Release: SKIDROW's "Fix" SKIDROW claimed their crack removed the DRM checks