After COINTELPRO was exposed, the FBI was forced to accept restrictions on they way they operated. In 1976, Attorney General Levy created guidelines intended to safeguard our Constitutional rights from FBI abuses. The guidelines were pretty strong, but almost immediately, subsequent AGs chipped away at them. The latest revision of the Guidelines was implemented in the waning days of the Bush Administration, under AG Mukasey.
Direct link: https://drive.google.com/file/d/0B9h3ZAGOL-0ucXR1dW5jYW44TWs
Original document name: AG FBI guidelines.pdf
FOIA or Government Document, Any, 2008