Would they need to get back to the sender? If so, they could always go the BTK route[0] and address the sender through the paper/website/show itself. [0] The "

Would they need to get back to the sender? If so, they could always go the BTK route[0] and address the sender through the paper/website/show itself. [0] The "BTK killer" asked in an anonymous letter to the police if they would be able to track him down if he sent subsequent letters on a floppy disk. The police took an ad out in the paper to tell him no, they couldn't, so he sent a disk. He wrote the letter in Microsoft Word and using metadata on the file they were able to track the killer down and arrest him.