Simplifying Privacy

The privacy considerations detailed so far provide a wide range of options for managing how location information is disseminated. There is little doubt that many users when presented with this information would not know what to do with it. However, those same users would be very definite about what privacy they expect.

Expressing user expectations as simple statements helps in understanding what the privacy rules need to contain. For instance, the following statements can lead to definite authorization policy rules:

• "Joanne wants her mother to be able to locate her at all times." The resulting rule simply includes the identity of Joanne's mother.

• "Helen wants all her business contacts to be able to locate her only when she is at work." Aside from a list identifying each of Helen's business contacts, this "want" can be interpreted in several ways. However, the most robust solution checks if Helen's location is the same as the location of her workplace. A presence service might also be able to identify work in other ways, such as with the Rich Presence extensions (see Reference 4).

• "Philip wants the Pizza Delivery Co. to be able to locate him only when he has ordered a pizza." The rule matches the identity of Pizza Delivery Co. with an extra condition that Ted has ordered a pizza. How this last is determined may be as simple as checking if Ted has made a recent phone call to Pizza Delivery Co.

Thus, this is just a matter of reducing the requirements down to a small set of use cases.

It is also helpful to understand how similar existing systems provide privacy protections and to evaluate their merits. For instance, instant messaging services provide a simple authorization policy: if a requester is on a "friends" list, permit; if they are on a "blocked" list, deny; otherwise, ask the user. To a certain extent this model is provided by the GEOPRIV common-policy and will likely dictate how it is used in the short term.

Simplifying privacy rules to the point where they can be easily understood makes the service more accessible. Complicated authorization rules are likely to be beyond all but the most enthusiastic of "power" users. Developers of user interfaces that capture privacy preferences need to ensure that these simple desires can be communicated easily.

Protecting the privacy of a user while still providing a viable location-based service remains a large and complex task. Providing users with reassurances about the protection of their privacy is important. Therefore, providing a simple means for a user to express their privacy preferences is likely to increase the adoption of these services.

Privacy considerations in the area of location services will remain an important component that determines its success. It is likely that a better understanding of the area through research will help provide technological solutions that improve user experience or data protection. Similarly, legislative protections that enhance privacy will continue to develop as location services for the Internet become more prevalent.