Someone wrote a letter to the FTC? Is this like some obscure government rule where the FTC can't do something until they receive a letter in the mail? What is

Someone wrote a letter to the FTC? Is this like some obscure government rule where the FTC can't do something until they receive a letter in the mail? What is this world we live in? Are they not aware of what is happening in the world? Do all government agencies enforce their mandates by mail order?