Elon Musk's battle with regulators in the United States shows no sign of slowing down, with the controversial billionaire resorting to Eminem lyrics in his latest court filing.
The Tesla CEO has been involved in an ongoing legal struggle with the US Securities and Exchange Commission (SEC) over tweets that make reference to Tesla's value.
In the past this has caused share prices to spike and dip, drawing accusations of price manipulation.
In 2018 it led to both Musk and the company being fined US$20 million each, with an order stipulating that any of Musk's tweets about the company must be approved prior to publication via a consent decree.
In the latest filing to a District Court in New York, however, Musk argues that the requirement to have his tweets pre-approved is an infringement on his first amendment rights of free speech.
"The First Amendment requires that agencies proceed with caution when constitutional rights are at stake, not seek to pursue any and all novel theories that broaden their authority at the cost of individual freedom," the filing stated.
It also referenced Eminem's 2002 hit song 'Without Me', with a change to the lyrics to refer to the SEC instead of the FCC (Federal Communications Commission).
"The [SEC] won't let me be or let me be me so let me see / They tried to shut me down," the filing states, a reference to a penalty against a radio station for playing the rapper's song that was later rescinded.
The filing also argued that it was irrelevant that the SEC had allowed a Tesla lawyer to pre-approve Musk's tweets because it still restricted his rights.
"The Commission first attempts to evade scrutiny for its unconstitutional restraint on Mr Musk's speech by arguing that an SEC-designed, court-enforced agreement involves no state action merely because the Commission has deputised a Tesla securities lawyer to pre-approve Mr Musk's tweets," lawyer Alex Spiro wrote.
"But it is irrelevant whom the SEC has tasked with this duty; Mr Musk's speech is restrained as a result of the SEC’s prosecution just the same."
Musk has previously argued he only signed the consent decree because he was "forced" to.
"Tesla was a less mature company and the SEC's action stood to jeopardise the company's financing. Defending against the SEC's action... was not in the interests of the company and its shareholders," he stated in a previous court filing.
That would put "undue risk" on the company, he argued. "I entered into the consent decree for the survival of Tesla, for the sake of its shareholders."
The SEC issued a new subpoena earlier this year, following Musk's tweets polling his millions of Twitter followers on whether he should sell 10 percent of his stock in Tesla, which sent prices sharply down.
In February the Wall Street Journal reported that it was over potential insider trading because Musk's brother Kimbal sold shares worth around US$108 million (NZ$161 million) a day before his brother posted the poll on social media.
Reuters later revealed Musk's subsequent selling of over 10 percent of his shares had already been committed to plan, two months before the Twitter poll.
Musk argues that the latest subpoena was issued in bad faith and it's just another example of the "harassment" he faces.
He also accused the SEC of leaking information about the investigation which "speaks volumes about the SEC's bad faith conduct".