Exposure of Sensitive Information Through Data Queries

When trying to keep information confidential, an attacker can often infer some of the information by using statistics.

In situations where data should not be tied to individual users, but a large number of users should be able to make queries that "scrub" the identity of users, it may be possible to get information about a user -- e.g., by specifying search terms that are known to be unique to that user.