Sheer nonsense and an urban myth. He was never silenced. Who could do it? He was endlessly promoting himself and his ideas. But as he grew older, the proportion of visionary speculation outstripped his practical accomplishment, and he was often talking about grand possibilities that no one understood how to accomplish, promising revelations that never materialized. Wireless power was never demonstrated. If you speak visions, but no ear can decipher your language---are you "silenced"? His final years were self-isolated and in penury, kept afloat by a stipend from his old partner, George Westinghouse. World War II was in full swing. There were other concerns to listen to.

The FBI was aware that Tesla's only heirs were in Serbia and doubtless motivated their action of sequestering Tesla's papers for assessment as to whether they might represent a threat in foreign hands. They enlisted Dr. John G. Trump to assess Tesla's material, which he found to be harmless and unremarkable. In 1952, on pressure from Tesla's nephew, Tesla's estate (in 80 trunks) was sent to Serbia in 1957. The idea that the FBI is holding his files of miraculous inventions is unsupported. There is no secret Tesla technology.