In this blog post, the Washington Post and the AP allege a politcal influence in FOIA requests. I have to say the reporting here is a bit sparse. If these organizations really cared about the FOIA process they would report on the fact that agency FOIA operations are not funded to the extent necessary, that badly needed FOIA training is an uphilll fight for agencies, and that it in some cases political appointees need to be involved in the FOIA process to make it work.
Is it possible that in some cases, a political appointee is ruling against a FOIA disclosure for a purpose that is not allowable? Maybe, but as FOIA requesters are aware, non-political appointees make withholding decisions that are incorrect - and they are consistently backed by the litigators at the Department of Justice.