More specifically, there's a FOIA exemption for this very situation. It's exemption 4, the business/financial secret exemption. A quote from justice.gov's FOIA

More specifically, there's a FOIA exemption for this very situation. It's exemption 4, the business/financial secret exemption. A quote from justice.gov's FOIA guide[1]: Exemption 4 of the FOIA protects "trade secrets and commercial or financial information obtained from a person [that is] privileged or confidential." (1) This exemption is intended to protect the interests of both the government and submitters of information. Its very existence encourages submitters to voluntarily furnish useful commercial or financial information to the government and it correspondingly provides the government with an assurance that such information will be reliable. The exemption also affords protection to those submitters who are required to furnish commercial or financial information to the government by safeguarding them from the competitive disadvantages that could result from disclosure. (2) The exemption covers two broad categories of information in federal agency records: (1) trade secrets; and (2) information that is (a) commercial or financial, and (b) obtained from a person, and (c) privileged or confidential. 1: http://www.justice.gov/oip/exemption4.htm#N_1_ http://www.justice.gov/oip/exemption4.htm#N_1_