The Biden campaign is once again pressuring Facebook to increase its censorship against President Donald Trump, sending a three-page letter to the social network urging it to clamp down on warnings from the President and his allies about the potential for voter fraud in the coming election.

The letter cited a video featuring the President’s son, Donald Trump Jr., warning Americans that Democrats plan “to add millions of fraudulent ballots that can cancel your vote and overturn the election.”

A recent sting by Project Veritas revealed mass ballot harvesting in Minneapolis, Minnesota, which the Minneapolis police department says it is investigating. Minnesota is a crucial swing state in the coming election. A Democrat whistleblower who spoke to the New York Post also recently revealed the existence of widespread, organized voter fraud on behalf of Democrat candidates.

Nevertheless, Facebook did add a note to the video featuring Don Jr’s warning, telling its users that “voting by mail has a long history of trustworthiness in the US and the same is predicted this year.”

In a statement, Facebook spokesman Andy Stone pushed back against the Biden campaign’s demands for more censorship.

“We’ve faced criticism from Republicans for being biased against conservatives and Democrats for not taking more steps to restrict the exact same content,”  said Stone in a statement to Axios. “We have rules in place to protect the integrity of the election and free expression, and we will continue to apply them impartially.”

Although Democrats continue to argue that Facebook isn’t censoring their opponents enough, the social network has already censored the Trump campaign, taking down an ad attacking the violent Antifa movement in June, following pressure from the Democrat-aligned pressure group Media Matters.

Allum Bokhari is the senior technology correspondent at Breitbart News. His investigation into Big Tech, #DELETED: Big Tech’s Battle to Erase the Trump Movement and Steal The Election, is currently available for purchase. The book contains exclusive interviews with sources inside Google, Facebook, and other tech companies, who explain Silicon Valley’s efforts to sway the election from behind the scenes.