Numerous (and potentially ambigous) types of services out there:
- Directory
Service
- This Web site places a user in a directory so that people can easily find their email
address.
- Certificate
Server
- This site collects directory and cryptographic certificate information from users and
makes them available to third parties under the users' preferences. This organization
could be considered an agent if it only releases information in the context of a privacy
proposal, uses this information on behalf of the user under their preferences, and the
user has complete control over the information. But what does it mean if they support
themselves through Web advertising (banners)?
- User
Profile Server
- This organization collects anonymous, user behavior information over multiple sites and
shares it with multiple sites in anonymous form.
- Web
Privacy Agent
- A privacy agent is located on an external Web proxy that allows users to maintain
multiple pseudonyms on that proxy under P3P control. The proxy also provides cookie
control and anonymity -- since sites cannot track the individual's IP address. This
organization could arguably be described as a P3P agent.