This is what the USPS says, but it might not be the final answer. If the requester is in the 9th Circuit (one of AK, AZ, CA, GU, HI, ID, MP, MT, NV, OR, WA) an

This is what the USPS says, but it might not be the final answer. If the requester is in the 9th Circuit (one of AK, AZ, CA, GU, HI, ID, MP, MT, NV, OR, WA) and especially if the requester is in the Northern District of California (SF Bay Area), there are court cases that may be relevant. Doug Carlson[1] requested basic data about post offices and post office boxes (location, hours, etc.), and the USPS claimed the information was commercial and therefore exempt from FOIA. In at least the case of the post offices, it went to the 9th Circuit Court of Appeals, which ruled in his favor [2], meaning that the law in the Ninth Circuit may not be on the USPS's side. (In the case of disclosing the locations of mailboxes, the USPS claimed a FOIA exemption based on the potential for using knowledge of mailbox locations to distribute chemical and biological agents, but it lost to Carlson in the Northern District of California [3]). I would encourage the requester to take the next step in a denied FOIA request and file a timely appeal with the USPS general counsel [4]. I'm not a lawyer, but you could probably find one who could write a convincing letter based on the current caselaw in the 9th circuit. Or try Doug Carlson himself, as his contact details are part of the public record [5]. [1] http://www.sfgate.com/bayarea/article/PROFILE-Doug-Carlson-Stamping-out-mail-2882873.php http://www.sfgate.com/bayarea/article/PROFILE-Doug-Carlson-S... [2] http://www.leagle.com/decision/20071627504F3d1123_11592 http://www.leagle.com/decision/20071627504F3d1123_11592 [3] Carlson v. USPS, No. C-02-05471, 2005 WL 756573, at *6-7 (N.D. Cal. Mar. 31, 2005) (concluding that disclosure of data pertaining to mailbox locations would not risk use of postal system to distribute biological or chemical agents because agency failed to demonstrate that such data actually could be used to determine mail collection routes). Found on p.206-207 of http://www.justice.gov/oip/foia_guide09/exemption2.pdf http://www.justice.gov/oip/foia_guide09/exemption2.pdf. [4] http://about.usps.com/who-we-are/foia/faq.htm#H10 http://about.usps.com/who-we-are/foia/faq.htm#H10 [5] http://prc.gov/prc-pages/library/dockets.aspx?activeview=SummaryViewSrvcList&docketid=N2010-1&docketpart=ServiceList&servicelistpart=ListOfPartyReps&attrID=0&attrName= http://prc.gov/prc-pages/library/dockets.aspx?activeview=Sum...