An atheist in the United States has filed a lawsuit demanding the right to use the car number plate "IM GOD".
Bennie Hart, from Kentucky, was first told that his licence plate was "obscene or vulgar".
He was then advised by US motor vehicle officials that it was "not in good taste".
He had used the same number plate with no problem in Ohio for 10 years but drove into trouble when he moved to Kentucky.
The Freedom From Religion Foundation said in a press release that they and the American Civil Liberties Union of Kentucky had filed the lawsuit.
They are challenging regulations that allow officials to deny personalised number plates based on "good taste" or on whether they communicate religious, anti-religious or political messages. And they argue that his number plate falls within the category of protected free speech.
Hart, an atheist since the age of 15, told the foundation: "I simply want the same opportunity to select a personal message for my license plate just as any other driver. There is nothing 'obscene or vulgar' about my view that religious beliefs are subject to individual interpretation."
In a phone interview, Hart told the Courier-Journal: "It's straight-out First Amendment civil rights. Somebody says, 'Well, gee you can't say that.' Well the fact of the matter is, I can say that."
He said the licence plate was meant to communicate that no one religion's view of God is more righteous than another's. "Nobody's been able to prove I'm not God and I can't prove I am."
Foundation lawyer Patrick Elliott said: "Hart has a right to select a personalised plate message that reflects his philosophical views, just as any other driver may select an individual message for their personalised plate. Just as others may select religious messages, Ben Hart, an atheist, has a right to comment on religion."
William Sharp, legal director of the civil liberties union, said: "Under the First Amendment, government officials do not have the authority to censor messages simply because they dislike them. And in this instance, personalised license plates are a form of individual speech equally deserving of First Amendment protection."
