AdvertBan doesn't use information obtained from users in any way, which can violate users' privacy
An unique identifier is assigned for each AdvertBan installation. This identifier is used only for distinction between paid users and free users.
AdvertBan sends a small percent of truncated visited urls to the AdvertBan server in order to update local ad filter cache in the browser. These urls are truncated to the minimum length required for ad filter cache update algorithm to work. Url truncation serves two purposes:
compliance with your privacy. Usually privacy sensitive information (session id, user id, page parameters) is stored in the end of the url, which is truncated before sending it to the AdvertBan server
network traffic savings
The source code of ad filters' update algorithm is available here.