Wii Transfer will by default automatically connect to a Riverfold server to download the latest list of game titles. This is used to improve the saved games list, because the Nintendo Wii uses 4-character game codes instead of the real game titles.
No private information is sent from your computer. The full URL that Wii Transfer connects to is:
http://www.riverfold.com/software/wiitransfer/GameCodes.plist
The file it downloads is an XML file in the standard Apple plist format. This file is saved inside your Application Support folder for later use by Wii Transfer. If the download preference is not set or if there is an error downloading the latest game list, a built-in list inside the Wii Transfer application package is used instead.
To disable the game titles download, open the preferences window (Wii Transfer Preferences) and uncheck the "Download game titles from Internet" checkbox.