Peter Gersten is a (now retired) lawyer specializing in FOIA requests for UFO documents. He filed suit against the CIA in U.S. District Court in 1977 for release of documents concerning UFOs. In Januray 1980 this resulted in over 900 pages of documents being released, although there was little in them that wasn't already known. There also was a reference to 239 documents which could not be released because of 'national security' restrictions.
He is the man behind CAUS (Citizens Against UFO Secrecy, based in Arizona). In this capacity he sued government agencies in order to get them to release official information regarding UFOs, aliens, etc.
Caus has a newsletter available which tracks his progress, provides forum for people who have sightings, non-UFO Sundays with heartwarming stories which restore faith in humans, and more.
Peter Gersten was the person who, in 1983, introduced Rick Doty to Linda Moulton Howe. (Linda Moulton Howe later claimed she was deceived by Doty, and that he deliberately misled her, though Doty denies this).