 Unsavory, harmful and vicious tactics have been employed—including anonymous attempts to break up marriages, disrupt meetings, ostracize persons from their professions, and provoke target groups into rivalries that might result in deaths.Intelligence agencies have served the political and personal objectives of presidents and other high officials.While the agencies often committed excesses in response to pressure from high officials in the Executive branch and Congress, they also occasionally initiated improper activities and then concealed them from officials whom they had a duty to inform.