Long was responding to a Twitter challenge where he was supposed to state a "controversial yet unproblematic opinion" ... and he wrote, "John Lennon was a bad guy."
The Philadelphia Eagles stud doubled down in all caps -- "JOHN LENNON WAS A BAD GUY AND IF THIS MAKES YOU MAD UNFOLLOW ME."
When asked why he felt this way, Long responded, "It’s easier for me because I don’t care for the Beatles. I don’t feel a need to cape for an abuser."
Long is clearly referring to Lennon's admission that he physically abused women -- something he touched on during a 1980 Playboy interview.
"All that 'I used to be cruel to my woman, I beat her and kept her apart from the things that she loved' was me. I used to be cruel to my woman, and physically -- any woman."
"I was a hitter. I couldn't express myself and I hit. I fought men and I hit women. That is why I am always on about peace, you see. It is the most violent people who go for love and peace."
"Everything's the opposite. But I sincerely believe in love and peace. I am not violent man who has learned not to be violent and regrets his violence. I will have to be a lot older before I can face in public how I treated women as a youngster."
In fact, his first wife, Cynthia, wrote a book and said Lennon once slapped her in the face.
When somebody tried to challenge Long and say, "People aren't just good or bad" -- he shot back, "Shut the f*ck up."