[1][2] Devices allegedly suppressed include perpetual motion machines, cold fusion generators, torus-based generators, reverse-engineered extraterrestrial technology, anti-gravity propulsion systems, and other generally unproven or physically impossible, low-cost energy sources.
[2][3][4][5] The alleged suppression (or weakening) is claimed to have occurred since the mid-19th century[6] and allegedly perpetrated by various government agencies, corporate powers, special interest groups, and fraudulent inventors.
The special interest groups are usually claimed to be associated with the fossil fuel or nuclear industry,[7][8] whose business model would be threatened.
[20] Notable proponents of the conspiracy theory include Gary McKinnon, a Scottish computer hacker who unlawfully accessed computer systems to look for evidence of a secret free energy device.
[21] Followers of the Tartaria conspiracy theory believe an advanced civilization called Tartaria destroyed by a "mud flood" now covered up by the world's governments once had free wireless energy.