No recipient or other person shall intimidate, threaten, coerce, or discriminate against any individual for the purpose of interfering with any right or privilege secured by section 601 of the Act or this subpart 101-6.2, or because he has made a complaint, testified, assisted or participated in any manner in an investigation, proceeding, or hearing under this subpart. The identity of complainants shall be kept confidential except to the extent necessary to carry out the purposes of this subpart, including the conduct of any investigation, hearing, or judicial proceeding arising thereunder.