"Spend any time around NASA public affairs specialists, as I do, and you'll eventually get the eye roll. It comes when someone inquires about aliens or faked moon landings or all manner of other nonsense. One of the more recent eye-rollers originated in Russia, where officials said sea plankton was growing on the exterior of the International Space Station. (It wasn't.) "If you think that's bad, you should Google 'NASA hiding,'" one space agency official told me. So I didand here are the first five things I found."
Keith's note: Of course NASA does not help itself with the conspiracy crowd when it funds quackery such as the warp drive project at JSC and the LENR project at LaRC - both of which defy conventional physics, have yet to yield any reproducible results, and for which NASA is not even willing to reveal budgets or objectives.