While the leadership of the John Birch Society took certain efforts to distances itself from overt anti-Semitic elements, the Anti-Defamation League felt that countering the JBS fell within its larger mandate to combat extremism in all its forms. The tactics used by the ADL to track and counter JBS activity, as documented in the subject files of the collection, included attempts to infiltrate the JBS headquarters office and local chapters, encouraging reports from unnamed informants, as well as tracking JBS membership by collecting pro-Birch letters to newspapers or tracing license plates observed outside Birch-sponsored bookstores.