Mike Tyson -- I'm Not Afraid Of Twitter ... People Always Told My Secrets

Mike Tyson says he wouldn't have had to worry about being put on blast on Twitter back in his heyday -- because when it came to girls, "They told anyway, so it was just like Twitter."

Tyson was at LAX with his wife Lakiha when we asked if social media makes it harder for celebrities and pro athletes to keep their private lives private ... and Mike told us, for him it wouldn't have mattered.

Check out the clip ... Tyson also responds to boxer James Toney -- who recently said he'd beat Iron Mike's ass if they get into the ring in a widely rumored comeback fight.

"I'm 50-years-old," Tyson said ... "anybody can beat me now!"