A Milwaukee man has filed a federal lawsuit against Sheriff Clarke, after the two exchanged words on a flight last month. 

That lawsuit claims Clarke, his deputies, and Milwaukee County violated his 4th, and 14th Amendment rights. 

According to Dan Black, Sheriff Clarke and six deputies detained, and questioned him at Mitchell International, after he shook his head at Clarke while boarding a flight in Dallas. 

Later that week, Black filed a complaint with Milwaukee County.

      "I would have been fine if I filed this complaint and he responded and apologized, I probably would have left it there," Black said Thursday.

Instead, Clarke's office responded to with a series of questionable Facebook posts.

Black says he's received death threats since he went public with his story.

      "It's horrifying, it's scary," he says. "I would lay awake at night thinking about this. How long until the cops show up at my door and plant something on me?" 

Black's Attorney, William Sulton, called Clarke's actions both on the flight, and responding to the complaint, outrageous. 

      "There's no question that Sheriff Clarke is exploiting the fact that the county cannot effectively check his power."

The six deputies who helped detain and question Black are also listed as plaintiffs. 

     "They had a constitutional obligation to stop the sheriff, and instead of doing that, they participated in it."

County Executive Chris Abele's Office declined to comment, as did Sheriff Clarke's Office. 

The lawsuit is calling for unspecific financial damages, as well as a change in how the county oversees Clarke. 

      "We are hoping the district court will retain jurisdiction over this action, and monitor the Sheriff's Office on a quarterly basis," he says. "To assure that this type of government abuse of power does not happen again."

Clarke has 21 days to respond to the lawsuit.