Retired CIA Agent John Brennan cauterized Obama's U.S. Passport records because the U.S. Passport applications contain incriminating evidence which could be used to prove Obama is ineligible for the Office of President of the United States. For example, a U.S. Passport applicant is required to identify any previous U.S. passports held by name and number.
During the 2008 campaign for the Democratic nomination, Obama said he traveled to Indonesia and Pakistan in 1982. Obama had to stop in Indonesia before he could complete his journey to Pakistan to renew his expired Indonesian Passport. Obama was issued a Certificate of Loss of Nationality in 1968 by U.S. Secretary of State Dean Rusk after Obama's mother had him taken off her passport as a family member who had naturalized in a foreign state. Obama didn't regain his U.S. Citizen until 1983 after he completed the naturalization process.
And finally, the most incriminating evidence against Obama's eligibility is Form DS-11, Application for U.S. Passport, identifies the document the applicant uses to verify eligibility for a U.S. Passport, i.e. Certificate of Naturalization. Anyone with a Certificate of Naturalization is disqualified from eligibility for the Office of the President of the United States.