John Lennon in his lifetime would also complain about being followed around by strangers that he did not know. Phone taps and other forms of surveillance. He stated that if anything ever happened to him or Yuko Ono it would be no accident. After his death, and many FOIA requests later, some portions of his File were finally released.
Direct quote from the movie.
“His activities were being monitored. He says that he thinks that they wanted him to notice. He was scared paranoid.
He believed all of his telephone conversations were being monitored.
He believed that he was being followed around New York City.
He believed that friends that he had thought were friends were secret Informants for different intellegence communities.
Another effect of the Sinclair thing was it probably further alerted the FBI, John Mitchell, Holdermin, ?, and Nixon that something needed to be done to neutralize John Lennon.”
“When it gets down to having to use violence then you are playing the systems games. The establishment irritates you, pull your beard and flick your face to make you fight, because once they have you violent then they know how to handle you.”