Property Index Numbers Not Excludable Under FOIA

In June 2018, the Office of the Attorney General published Public Access Opinion 18-009 which emphasized that property index numbers were not exempt from disclosure under the Illinois Freedom of Information Act (FOIA).

The Attorney General (AG) published this opinion in response to a case where an attorney submitted a FOIA request to the City of Chicago Department of Business Affairs and Consumer Protection seeking a list of all properties that had been granted a Commissioner’s Adjustment. The attorney requested that property index numbers be included in the response. The Department provided records, but redacted the property index numbers, claiming they were exempt as “private information” under Section 7(1)(b) of FOIA, or, in the alternative, as “an unwarranted invasion of personal privacy” under Section 7(1)(c).

The opinion points out that a property index number identifies a specific parcel of property, not an individual. Furthermore, they are readily available to the public on governmental websites and are subject to public inspection by statute and therefore are not private information. The fact that a property index number could be used to more readily seek out the identity of the owner did not sway the AG, who reasoned that “the fact that a person can combine various available pieces of information to ultimately identify otherwise exempt information does not render that information exempt from disclosure.” Additionally, the release of property index numbers is not an unwarranted invasion of personal privacy since the numbers are readily available and since there was a substantial public interest at stake in this case, namely ensuring that the adjustments at issue were being granted equitably.

Most importantly, the opinion cites a four-factor test for determining if the release of otherwise personal information contained in public records constitutes a “clearly unwarranted invasion of personal privacy:” 1) the requestor’s interest in disclosure, 2) the public interest in disclosure, 3) the degree of invasion of privacy, and 4) the availability of alternative means of obtaining the requested information.

The result of this opinion is that property index numbers, and likely many other types of personal identifiers that do not identify individuals directly or that can be combined with other readily available information to identify individuals, cannot be exempted from FOIA requests.