That's not their job. Congress should specify which agency is responsible for checking credentials and how that needs to be done. Not holding my breath waiting for that to happen, though.
Further, Mr. Vieira cited a fraud ruling in a 1977 case called U.S. v. Prudden, which he feels applies in this case.
“Silence can only be equated with fraud when there is a legal and moral duty to speak or when an inquiry left unanswered would be intentionally misleading,” the ruling reads. “We cannot condone this shocking conduct ... If that is the case we hope our message is clear. This sort of deception will not be tolerated and if this is routine it should be corrected immediately.”
Now if only you would quit trying to silence the opposition and wait for justice to run it’s course.