Sony has forced a programmer to remove from his Web site code that changed the behavior of its Aibo robot dog.
According to a report in New Scientist, the programs gave Aibo new functionality. One, called Disco Aibo, made the robotic canine dance to music.
Sony protested, saying that the applications used proprietary and encrypted code. The Japanese company demanded the removal of the programs, along with details of Aibo's software protection.
The anonymous enthusiast has complied but insists that he never published any specific details of how to break the security of Sony's Memory Stick storage media, which stores the programs that define Aibo's behavior.
New Scientist reported that some figures in the robotics community are unhappy that Sony clamped down on efforts to customize Aibo. They believe that the community of Aibo hackers would have benefited from knowing how to successfully modify the dog's behavior.
Sony launched the original Aibo robot dog in 1999 and sold over 45,000 models. An updated, and cheaper, version hit Japanese shops in November 2000.
Two new models were launched this autumn. "Latte" and "Macaron" are described by the company as "cute, cuddly and intelligent," and Sony has predicted they will be popular items during the holiday shopping season.
Graeme Wearden reported from London.