"Q, why don't you use fantasy 'tech' that my group of alien researchers know to exist?"
Answer: Because disinformation agents prey on the gaps in people's understandings and on their faith in the power of government. Disinformation is very easy to spot when you understand one simple thing - it all glorifies the State into an unassailable power. Disinformation creates the illusion of an all-knowing, all-powerful state that the general public is completely powerless against. Mind control technology. Technology "50 years ahead of the civilian world." Etc.
Disinformation agents will typically use poorly understood topics, or those that are only understood on a tangent by most educated people, to justify their claims. See Bob Lazar as a classic example. It is always just on the edge of believable. We have research that shows noisy electronics can make people feel uncomfortable or be more prone to hallucinations - so fancy mind control devices using radio components 50 years ahead of the enthusiast market become the subject.
Beware of claims to the extraordinary. This is doubly so if the claim gives the government an impossible-to-assail position. "Perfect weapons," and other such tools should be regarded with suspicion.