On June 18, Facebook announced that it deleted ads runs by Donald Trump's re-election campaign for violating its organized hate policy. These ads targeted what the Trump campaign deemed Dangerous MOBS of far-left groups, had an upside-down triangle.

The Anti-Defamation League explained that the triangle bears a striking resemblance to the symbol used by the Nazi regime to categorize political prisoners kept in concentration camps. Facebook spokesperson, Andy Stone told CNN that the social media giant's policy restricts using a symbol adopted by a banned hate group to categorize political prisoners without a frame of reference that either condemns or discusses the symbol.

Aside from offering this explanation, Facebook also confirmed in a statement that the hate group it was referring is Nazis. The ads were aimed at the far-left group Antifa, urging Trump supporters to back the president's efforts to label the group a terrorist organization.

After coming under fire from netizens for the ad, the Trump campaign said the red triangle was a widely-used symbol by Antifa. The campaign shared multiple links to posters, magnets, and sticker websites that sell unofficial merchandise bearing the symbol. The campaign didn't point to examples of Antifa members wearing the symbol.

Admitting that a few Antifa activists have used the symbol, ADL said it is not common. Facebook's political ad library states that ads with offending symbol began surfacing on June 17 on the president's main Facebook page, vice president Mike Pence's Facebook page, as well as the Team Trump campaign page.

Facebook data reveals that the paid ad was seen one million times in users' feeds on the president's page alone. Director of communications for the Trump campaign, Tim Murtaugh released a statement claiming the red triangle is a symbol used by Antifa activists.

Moreover, Murtaugh pointed out that Facebook has an inverted triangle emoji that can be used by its users, despite looking exactly like the symbol featured in ads run by Trump's campaign. Aside from that, he pointed out that the symbol isn't even included in the Anti-Defamation League's database of symbols of hate.

In its defense, the ADL said that its database is not a database of past Nazi symbols, adding that it comprises symbols used by modern extremists in America. Facebook's decision to delete Trump's ad is likely to increase tensions between Silicon Valley and the White House.

Facebook CEO Mark Zuckerberg faced strong criticism last month for not removing Trump's ad that said looting leads to shooting, amid nation-wide protests for racial injustice. Twitter labeled the same post as encouraging violence on its platform.