Suppression? If Rossi's claims to be selling a one megawatt thermal plant which worked by nuclear fusion, do you *really* think it could be suppressed if it were real? Rather than sold by the thousands immediately for use in simple space heating applications, for example in remote areas or where fuel and electricity were costly? And simply so the process could be studied and perhaps reverse engineered or improved and produced under license? By the hundreds of thousands? Immediately? You really believe such a thing could be "suppressed"? By whom and exactly how in this modern world of social media and instant communications to the entire world? What crappola and nonsense!
It is a hallmark of belief in conspiracy theories and suppression of what turn out to be high tech fraud, that the proponents grossly and stupidly underestimate the importance and consequences of the invention, were it real. I've seen that with Steorn, Tilley, Bedini, Howard Johnson, and Dennis Lee's scams to name a few proven scams and failures. None of the claimed inventions from those sources could ever be suppressed were they real and neither could power at the claimed level from Rossi or Defkalion or Brillouin or name a claimant for kilowatts...