Your computer's IP address will always be logged when you load the game client. It is not tied in any way to your username, except possibly if a server error occurs. Gameplay results are logged permanently, but without information identifying you.
Pretend You're Xyzzy is a Cards Against Humanity clone, which is available at cardsagainsthumanity.com, where you can buy it or download and print it out yourself. It is distributed under a Creative Commons - Attribution - Noncommercial - Share Alike license. This web version is in no way endorsed or sponsored by cardsagainsthumanity.com. You may download the source code to this version from GitHub. For full license information, including information about included libraries, see the full license information.