The main focus of the PSB are activities which threaten national security and therefore, their work is similar to Special Branches of British and Commonwealth police forces.
[7] The PSB had been the leading agency to investigate reports that Aum Shinrikyo had acquired names of 3,000 Honda executives and sensitive data from government ministries and other important facilities via Aum-created software.
[16] An ex-Japanese Air Self-Defense Forces warrant officer had been investigated by the PSB in 2002 for divulging military secrets under the Mutual Defense Assistance Agreement to a Russian GRU operative, who was identified as Aleksei Shchelkonogov.
[20] On December 15, 2020, PSB officers investigated the activities of a South Korean man living in Tokyo accused of hacking into the Chongryon website and the Korea News Service.
[21] After a discovery of sophisticated radios by police during a raid on a JRCL Revolutionary Marxist Faction safehouse on April 10, 1998, PSB officials had reorganized their communications network to better safeguard it against unwanted intrusions.
[3][22] In 2014, a report was made thanks to a leak that PSB officers were conducting covert surveillance activities on Muslims residents living in the Greater Tokyo Area.