Technically, any repack that bypasses Ubisoft’s launcher is copyright infringement. However, many users who search for actually own the game on DVD or Steam but cannot install due to:
System requirements for Assassin's Creed Revelations - Ubisoft
Assassin's Creed: Revelations is an action-adventure game developed by Ubisoft Montreal and published by Ubisoft. The game was released in 2011 for PC, PlayStation 3, and Xbox 360. It is the third main installment in the Assassin's Creed series, following Assassin's Creed (2007) and Assassin's Creed II (2009).