Last season he flew it every day Seattle was in the playoffs until his homeowners association told him it was a violation of the rules. After he took it down, the Seahawks lost at Atlanta.
This year, Carlson had only been flying the American flag when he got another letter from the homeowners association, accusing him of flying the 12th man flag and threatening a fine.
"I was upset because I mean, for me, flying my Twelfth Man flag when the Seahawks are away, makes me feel i'm a part of them," he said.
The Daily Herald reports Carlson now has a lawyer and he's fighting back. The lawyer says Carlson will fly the American flag as he wishes and will also fly the 12th man flag on game days.
"I'm just a fan," he said. "I don't feel like I'm doing nothing wrong."
Carlson now believes flying the flag might somehow make a difference for the team.
"I said, 'I don't care, I'm going to put the flag up.' And sure enough, man, the second half comes along. I mean, look what happened," he said.