Number one on the list of top-ten reasons not to mess with Northern Westchester resident David Letterman: You won’t win. When a CBS staffer tried to extort $2 million from Letterman, he worked with the district attorney’s office to nab the blackmailer with a fake check. Letterman isn’t all in the clear, though. On his show last night, he admitted to having affairs with women who worked for him on his show. He made the admission on-air because, he said, ““I feel like I need to protect these people. I need to certainly protect my family.”