Far-right blogger Robert Spencer logged into fundraising site Patreon last week expecting to see how much money he had raised in a new bid to build a studio for his YouTube videos. Instead, Spencer found out his nascent funding campaign was over about as soon as it had started: at Mastercard’s request, Patreon was kicking him off the platform.

“Mastercard has a stricter set of rules and regulations than Patreon, and they reserve the right to not offer their services to accounts of their choosing,” Patreon wrote in an email to Spencer, a leader in the “counter-jihad” movement. “This is in line with their terms of service, which means it’s something we have to comply by.”

Mastercard doesn’t own Patreon, and both companies were vague about what had prompted Mastercard to flag Patreon payments to Spencer.

In a statement on Spencer’s Patreon ban, Mastercard said it sometimes flags “questionable or illegal content.” Patreon, in a series of tweets, wrote that Mastercard “required us” to take down Spencer’s account.

That leaves Spencer, who received the couple of hundred dollars he had already raised on Patreon and said he doesn’t have a Mastercard himself, mulling a lawsuit.

Most of the conservative conversation about tech bias has focused on social media companies, with congressional Republicans holding hearings over what they say are unfair punishments from YouTube and purported “shadow-banning” on Twitter. But the next front in the clash between with Silicon Valley looks set to center instead on right-wing personalities’ pocketbooks, as fundraising platforms and payment processors crack down on the right.

White supremacist groups have been financially under pressure online since the fatal 2017 rally in Charlottesville, Virginia Spencer’s views, on the other hand, are relatively mainstream within the Republican Party and right-wing media, suggesting that a broader enforcement from the credit card companies could be ahead.

While he’s made a number of anti-Muslim statements, including writing in his 2017 memoir that he’s fine with being “the right kind of Islamophobe,” he’s also regularly appeared on Fox News. Spencer told The Daily Beast that his ouster from Patreon is “obviously” the latest example of tech giants’ bias against conservatives.

Spencer blamed the Mastercard response on the Southern Poverty Law Center, the anti-racist group that has dubbed him an “extremist.” SPLC spokeswoman Heidi Beirich told The Daily Beast that Mastercard contacted the organization ahead of warning Patreon about Spencer’s account, although Beirich said the Mastercard response was prompted by a separate campaign from Color for Change, a group that has pressured financial companies to ban extremist figures.

In a press release last week, Color of Change said its members had pressed Mastercard to “take proactive steps to stop processing payments for white supremacist groups.”

“We want PayPal, we want Mastercard, we want all of them to stop servicing hate groups,” Beirich said.

The payment crackdown has even reached fundraising platforms that fringe right-wing figures set up as backups for personalities banned from the main sites.

In July, Canadian right-wing activist Faith Goldy was kicked off PayPal. Goldy then told her fans she would instead be taking payments through Freestartr, the Kickstarter-style site started by conservative media gadfly Charles Johnson.

In the past, Johnson’s fundraising sites have helped fund legal expenses for neo-Nazi Andrew Anglin and a man accused of sending journalist Kurt Eichenwald a .gif file meant to induce a seizure. But Freestartr was soon also banned from PayPal and payment processor Stripe, leaving Goldy and the other right-wing figures who had turned to Johnson’s site bereft of yet another way to get money from their fans.

Both Spencer and Johnson say they’re planning legal action over their payment issues. Like Spencer, Johnson blames the SPLC, claiming his site was targeted “because we allowed others to use our platforms to defend themselves against their lawfare.”

Asked about Johnson’s claim that the SPLC is behind Freestartr’s payment issue, Beirich said that much of the money that went through the site was sent to “bad guys.”

“We’re glad that money isn’t getting the hands of neo-Nazis and white supremacists,” Beirich said.

Losing access to online fundraising has forced far-right groups to resort to more old-fashioned methods. White nationalist group Identity Evropa tweeted in July that, after being hounded off various online fundraising platforms, it would now have to accept donations through a post office box.