Techniques for protecting non-public information in a mobile environment are provided. A request for non-public information about users in a mobile environment is received. Privacy policies, non-public and optional public information about the users affected by the request are determined. An optional privacy impact indicator is determined based on how satisfying the request increases the current public information about the users. Crowds of users having similar attribute name/values are optionally determined. User and optional requestor privacy policies which associate threshold release criteria such minimum crowd size, minimum consideration with the non-public information are determined. A privacy agreement is reached for the disclosure of the requested non-public information based on the compatibility of the requester and user privacy policies. Privacy protecting transformations are optionally determined and applied to create crowds or groups associated with the requested attribute.