Japanese police today arrested a man being suspected of behind a computer hacking campaign following an exhaustive hunt that at one stage had authorities tracking down a cat for clues. Yusuke Katayama, 30, was arrested on charges of using a remote computer and sending a mass-killing threat to a comic book event after months of evading investigators with a series of vexing cyber-riddles, according to broadcaster NHK. The channel aired footage of detectives escorting a chubby man with glasses into a police station. He is believed to have sent numerous threats from computers around the country, including against a school and a kindergarten attended by grandchildren of Emperor Akihito.