The publisher alleges that OEM had agreed to abide by--and thereafter ignored--an array of security procedures that could have prevented the leak. Ubisoft further alleges that OEM admitted to not following through on its security commitments and causing the leak. One such security procedure was to prevent copies of the game from ever leaving OEM's premises. Ubisoft said it tracked the earliest connections to the pirated copy of the game online and found that they were coming from the home of an OEM employee. An OEM-manufactured copy of the game was later found at the employee's residence, though the suit doesn't specify when that copy was found.

According to the industry-tracking NPD Group, the PC edition of the game sold more than 40,000 copies at US retailers through June. Ubisoft claims the leaked edition of the game was downloaded more than 700,000 times, costing the publisher millions of dollars. In addition to lost sales as a direct result of piracy, the publisher also claimed its reputation was hurt by the leak as well. Ubisoft says it included a bug in the pre-release Assassin's Creed for security reasons that would cause the game to crash partway through. The bug was supposedly removed from the retail edition, but a mix of negative reviews of the leaked and bug-equipped pirated version of the game and legitimate reviews of the retail edition created customer confusion and caused "irreparable harm" to its reputation, Ubisoft said.