People on Yahoo make wild claims all the time both positive and negative claiming they have a source. When they do not provide a link it is usually a fake. I believe Nikko has been called out on several other claims in the past.

As far as the SEC is concerned, you would pretty much have to post something that "looked" very official AND they would likely need to see that you profitted from the deception. Even then, it is not likely anyone would go after them. They just don't have the time or desire to go after them.