Footballer-turned-boxer Curtis Woodhouse came face-to-face with the man that abused him on Twitter for eight months.
Following Woodhouse's visit, which he claimed occurred because he was worried for his family, the pair met on live television during a ITV's Daybreak.
"I was really childish," said O'Brien. "Looking back on it, I realised that I had done a wrong thing. I can only offer my deepest apologies to anyone I ever abused on Twitter. I've let everyone down, friends, family, and I do feel really embarrassed."
Woodhouse drove more than 60 miles to find O'Brien's address.