According to this Reddit post
Summers or his followers also use Reddit for dishonest proselytizing.
r/AlienAgenda AND r/AlienAbduction are both Propaganda fronts for the mendacious NEW AGE, UFO CULT called: ALLIES OF HUMANITY, from Boulder, CO. These subreddits serve as a recruitment tool and a disinformation campaign for the followers of MARSHALL SUMMERS, whom they believe is the “NEW MESSIAH”
The "Marshall Vian Summers" Youtube channel advertises on Youtube. The top result when I searched youtube for "area 51" or "aliens" is an advertisement for their video "The Alien Agenda." See screenshots here: [imgur.com
This kind of advertising costs a pretty penny.
The ad text is "Allies, Rescuers or Invaders? Disclosure interview. Watch now."
Once again, this is dishonest advertising. "Disclosure" is the holy grail of the UFO-community. Many in the community believe the government has secret files that prove that aliens have visited earth and are hoping/pushing for disclosure of these secrets. The ad plays into this by promising a "disclosure interview," which of course the advertised video isn't.
I watched the advertised video and didn't find it convincing at all. The stuff about aliens seems very far fetched to me. Granted, there were some interesting (but not original) spiritual insights interspersed between the vague sci-fi stuff, and when you don't focus on Summers' nervous mouth-tic he comes across in a soothing, reassuring way. I can see why some people get under his influence.
From the SkepDic entry on Summers:
Will some people find comfort and solace in the messages of Summers? Of course. Some may even find them to be inspiring. Does that mean they were genuine? No. Is the Society for the New Message from God, founded by Summers in 1992, a cult? I don't know, but one sure sign those considering joining Summers should look for is this: are you being encouraged to separate yourself from your family and friends who don't accept the authenticity of the prophet? If you are, run for the exit. Whatever comfort you are given by the charisma, joy, love, caring, and seeming wisdom of Summers or others trying to recruit you, it will not last, it is not genuine, and you will eventually regret the day you gave your mind over to a charlatan.