Now, a lawyer is taking the state Department of Motor Vehicles to court.
Frank Shoemaker applied for the personalized tags "NE420."
But his request was denied.
The DMV says 420 is associated with pot smoking -- stoner shorthand for let's get high.
The Nebraska chapter of the American Civil Liberties Union filed the federal lawsuit on Shoemaker's behalf.
The ACLU says the DMV is violating Shoemaker's free speech rights.