The Ba'neth were a mysterious, paranoid, extremely xenophobic and reclusive Delta Quadrant race of multipeds. The Ba'neth had created sophisticated cloaking technology for their ships, bases and themselves. They devoted most of their time to monitoring unknown alien ships passing through their territory by accessing computer records. They would also use neural disruptors on people to ensure that if they survived a shot from it they would not remember what they looked like.
Until 2376, the Kesat government denied their existence. However, when a Ba'neth assaulted the Federation Starship USS Voyager's Security chief Lieutenant commander Tuvok during one of their investigations, Captain Janeway, with assistance from Kesat security deputy investigator Naroq and experimental technology developed by him, were able to locate one of their bases and forced them into giving them the disruptor in exchange for surrendering the technology capable of piercing the Ba'neth cloak. (VOY episode: "Riddles"; ST reference: Star Trek: The Magazine)