Newly released FBI files show agents across the country and at the highest level of the agency investigated "Deep Throat" — the 1972 porn movie, not the shadowy Watergate figure — in a vain attempt to roll back what became a cultural shift toward more permissive entertainment.

The documents released to The Associated Press show the expanse of agents' investigation into the film: seizing copies of the movie, having negatives analyzed in labs and interviewing everyone from actors and producers to messengers who delivered reels to theaters.

All of it in a failed attempt to stop the spread of a movie that some saw as the victory of a cultural and sexual revolution and others saw as simply decadent.