Do they not have the knowledge to do this, or do they simply have nothing to show for it?
From Ross Coulthart to even Grush, everyone could create anonymous emails and enter forums on the deep web, then publish everything they know and ask any trusted friend or ufologist to publish the link and the post as if he had found it while browsing the internet. As they must know a lot, they could disclose all the names involved, making this falsifiable.
Why doesn’t anyone ask them to do this? No reason to hesitate unless you don’t know anything.