The Federal Privacy Act 5 U.S.C. 552a protects the privacy of individuals whose private information could be disclosed in the course of responding to a Freedom of Information Act (FOIA) request. Failure to take this act into account could severely limit the information that you might otherwise be able to obtain.
If you know a private individual who may have some privacy interests at stake in the information you are requesting, it may be a good idea to accompany your FOIA request with his or her signed waiver or release of rights under the privacy act. For example, a local group seeking information about surveillance by government officials submits a FOIA on behalf of each of its members and for the group identified by name. At the same time the protestors each release their Privacy Act rights so that the responses to the group do not have all of their the names blacked out.
Be sure to use a form that the agency will accept. In general, always use the form published by the agency when it one is available (See an example)
Helpful link: http://usgovinfo.about.com/library/weekly/aa121299a.htm