How is well is our privacy protected on the Social Web? Of course, you can (and should) take some basic precaution measures, like not giving away sensitive information that can be used for financial fraud against you. However, there are issues beyond our hands that depend on how the Social Web handles our information.

Google recently published a paper entitled “(Under)mining Privacy in Social Networks”. The paper outlines some possible threats and proposes a number of counter-measures. In particular, the issues identified have to do with:

1. Activity Streams: These are collections of actions we perform on the Social Web, e.g. adding a friend, or posting a video. We may not be aware of all the actions fed into our activity stream. Also, we may not be able to control who sees our activity stream. For example, when Facebook introduced Beacon, purchases that I would make on eBay would be fed into my activity stream and would also be available to my friends.
2. Unwelcome Linkage: This happens when web links reveal information about us that we did not intend to.
3. Merging Social Graphs: It is possible to uncover personal information by merging data from different Social Web sites.

Getting complete control over the construction and publication of your activity stream is the key. The authors propose a solution in the form of a privacy warning system. When you upload information on the Social Web, you should be warned whether this information could be used to make connections about you.