Immigration judges are career civil-service employees in the Department of Justice's Executive Office of Immigration Review (EOIR). They preside over 'deportation, exclusion, removal, recission, and bond' proceedings for noncitizens charged with violating the immigration laws. Their decisions are final unless appealed to the Board of Immigration Appeals (BIA). The BIA's final decisions are subject to judicial review. In 2006, in the face of mounting public concerns about 'immigration judges who fail to treat aliens appearing before them with appropriate respect and consideration and who fail to produce [an acceptable] quality of work,' then-Attorney General Alberto Gonzales launched a 'comprehensive review of the immigration courts.' The Attorney General announced revised training and evaluation procedures for immigration judges and instituted a requirement that new judges pass a written knowledge examination before hearing cases. In May 2010, the Department implemented a new complaint database. Allegations of inappropriate conduct by an immigration judge go into the database as a complaint and get assigned a complaint number for tracking purposes. The Office of the Chief Immigration Judge (OCIJ) oversees the process of receiving, reviewing, tracking, and responding to complaints against immigration judges. The government periodically makes available to the public statistical information about complaints and the complaint process. In November 2012, American (P) submitted an FOIA request to the Department of Justice seeking information about complaints filed against immigration judges. P's request sought the following information: (1) All complaints filed against immigration judges; (2) All records that reflect the resolution of complaints filed against immigration judges, including the type of informal action taken, if any, or formal discipline imposed, if any; (3) All records that reflect the reasons for resolving complaints against immigration judges and/or findings relied on to resolve complaints against immigration judges, including any reports or memoranda from the Department of Justice Office of Professional Responsibility (OPR) or Office of the Inspector General (OIG); (4) All records incorporated by reference in documents that reflect the resolution of complaints filed against immigration judges; and(5) An index of the records described in paragraphs (2), (3), and (4) to the extent that those records constitute final opinions, including concurring and dissenting opinions, as well as orders, made in the adjudication of cases, pursuant to 5 U.S.C. § 552(a)(2)(A). After more than six months had gone by without a response, P filed this lawsuit. EOIR (D) began a series of rolling disclosures. By April 2014, D had disclosed some 16,000 pages of documents encompassing 767 complaint files, D redacted from those records information it deemed exempt from disclosure under FOIA Exemptions 5 and 6. Exemption 5 covers information that would be privileged from disclosure in litigation. Exemption 6 covers 'personnel and medical files and similar files the disclosure of which would constitute a clearly unwarranted invasion of personal privacy.' D redacted immigration judges' names and other identifying information from the disclosed complaint files and identified each immigration judge by a unique three-digit code in order to permit P to connect complaints to a particular judge and to identify patterns or track the progress of discipline. D redacted other information falling outside any of FOIA's enumerated exemptions, including, information deemed to be non-responsive to P's request even though found within a responsive record. P challenged the redactions under Exemption 6 and the redaction of non-responsive information in responsive records. The district court rejected P's arguments and granted summary judgment to D. P now appealed.