Assassin's Creed 4 hides a Watch Dogs secret

Watch Dogs may have been delayed to next year, but if you play Assassin's Creed 4: Black Flag, you'll get a small Easter egg regarding Ubisoft's next open world game. Spoilers follow. When exploring Abstergo Entertainment in the present day, you'll be able to hack into computers and get files that reveal the inner workings of the Templar-operated corporation. In one email, you'll see ctOS--the operating system that runs Chicago in Watch Dogs--pitched as a security option for Abstergo. Yes, technically the world of Watch Dogs is one and the same as the world of Assassin's Creed. That will certainly open up interesting opportunities in the future. Here's the email:
So what is ctOS? - CONFIDENTIAL: "Privacy is security." - INTEGRAL: "How did we ever do business without it?" - ACCESSIBLE: "The touch of a button!" - AVAILABLE: "We're everywhere... all the time." - STABLE: "It just WORKS." Put simply, ctOS is the most stable and user-friendly software security-controller ever devised. Can ABSTERGO afford to pass up perfection?

You can find this Easter egg rather easily