Most venture capitalists in Silicon Valley have a “vice clause.” No investments in drugs, weapons, alcohol, or pornography. A fifth prohibition may be emerging: no dictatorships.

Silicon Valley is awash in money pouring out of repressive countries such as Russia, China, and Saudi Arabia in search of credibility. Oligarchs and corrupt officials from these regimes, as well as the state itself, are looking to invest billions of dollars, much of it ill-gotten through state-sponsored fraud, oppression, assassinations, and immiseration of its citizens.

In the last 10 years, startups’ and VCs’ doors were flung open to accept their money. The Chinese government and state-owned entities back more than 20 Silicon Valley venture capital firms, Reuters reports. Russian oligarchs have seeded multiple investment funds. Yet no one has been embraced by the US technology industry like Saudi Arabia. Saudi investors have directly participated in investment rounds totaling at least $6.2 billion over the last five years with big bets on Lyft, Uber, and Magic Leap, among others. A $45 billion investment (with one more on the way) in SoftBank’s venture funds makes Saudi Arabia the largest single investor in US startups (paywall). That doesn’t even account for private investments, potentially worth billions of dollars, by the Saudi royal family and its inner circle. Just the top known investment rounds with Saudi participation are included in the table below.

Company sector investment round (millions; USD) Saudi investor Uber rideshare platform $11,321 Public Investment Fund Lyft rideshare platform $4,915 Kingdom Holding Magic Leap augmented reality $1,888 Public Investment Fund Lucid Motors car manufacturer $1,131 Public Investment Fund Virgin Galactic* aerospace $280 Public Investment Fund Desktop Metal industrial manufacturing $273 Saudi Aramco Energy Ventures Beamreach Solar energy $239 Riyadh Valley Company Snap social media network $250 Prince Alwaleed Bin Talal of Saudi Arabia Siluria Technologies oil and gas $151 Saudi Aramco Energy Ventures, Digital Signal facial recognition technology $125 Technology Control Corporation Rive Technology oil and gas $85 Saudi Aramco Energy Ventures

But the recent killing of Saudi exile and Washington Post columnist Jamal Khashoggi threw a harsh light on such investments. Saudi officials admitted to killing Khashoggi at its consulate in Turkey (likely under orders of its crown prince Mohammed bin Salman) due to a “fistfight” gone wrong. They’ve rejected Turkish allegations (paywall) that 15 Saudi men, many linked to Saudi security services, flew into Istanbul with a bone saw, severed Khashoggi’s fingers, and then killed and dismembered him.

So the Saudis are personae non gratae for the moment in the tech world. Executives from Uber to Google bailed on Saudi Arabia’s “Davos in the Desert,” and abandoned advisory roles on Saudi projects. A few entrepreneurs are putting their money where their mouth is. Richard Branson, who suspended a $1 billion Saudi investment in Virgin’s space ambitions, said ”the disappearance of journalist Jamal Khashoggi, if proved true….would clearly change the ability of any of us in the West to do business with the Saudi government.”

The Data Guild, a small startup accelerator, announced on Oct. 22 it would not take money from Saudi Arabia, China, Russia, and other repressive regimes in a Medium post. Its founder David Gutelius says he’s halted talks with firms who accepted money from Saudi Arabia’s sovereign wealth fund, as well as from proxies for the Chinese government and Russian oligarchs. “For far too long and especially over the last 15 or so years, venture capital has been a washing machine for tainted investment capital seeking legitimacy,” Gutelius wrote.

Fred Wilson at Union Square Ventures suggested this acceptance may be waning. A founder in one of his firm’s portfolio companies emailed to ask about the provenance of his fund after internal questions arose at the company. “I expect to get more emails like this in the coming weeks as the startup and venture community comes to grip with the flood of money from bad actors that has found its way into the startup/tech sector over the last decade,” Wilson wrote in a blog post on Oct. 21. “’Bad actors’ doesn’t simply mean money from rulers in the gulf who turn out to be cold-blooded killers. It also means money from regions where dictators rule viciously and restrict freedom. It could also mean money from business interests which profit by poisoning us with opioid addiction or warm our planet with fossil fuels.” (Wilson does not mention Saudi Arabia in the piece, although it is strongly implied.)

Shahin Farshchi, a partner at the venture firm Luxe Capital, said there’s enough capital available to avoid taking money from bad actors. Founders are justified in forcing the issue with VCs who refuse to disclose their backers, known as limited partners. “It’s a fair question for any founder to ask: what is the source of my capital…and is the benefit of my hard work going to be used to hurt others?” he said. “Shouldn’t this question already been asked?”

Yet few can claim to have no ties to Saudi money and other repressive funding sources, given the recent influx of cash in Silicon Valley. Farshschi said Luxe Capital’s portfolio companies, like many others, have Saudi investors (he was unable to immediately confirm if the fund’s limited partners had Saudi ties). Wilson said Union Square Ventures sold its pre-IPO stake in Twitter to an entity that turned out to be a front for investors from the Middle East, something it had not inquired into before the sale.

Is this the beginning of a trend? So far, the only investors to make explicit statements rejecting Saudi money are not major players in Silicon Valley’s ecosystem, or already get their cash from elsewhere. Most would not respond to inquiries. Andreessen Horowitz, Khosla Ventures, Sequoia Capital, True Ventures, 500 Startups, Y Combinator, along with other firms and industry associations in venture capital and limited partnership investors all declined to comment on the record.

Venture investor Jonathan Nelson, the founder and managing director of HACK Fund, says the industry is keeping a low profile. Nelson, who invests heavily outside the US, plans to attend a startup conference in Saudi Arabia’s capital Riyadh later this year. He hopes by working directly with startup communities, even those under repressive regimes such as many in the Middle East, citizens will be empowered to pursue reforms such as women’s rights, and create jobs not dependent on government corruption.

Yet the topic seems too highly charged for many venture capitalists to even discuss. “I‘ve been asked to recruit other VCs from the US” for the Saudi startup conference, Nelson said by phone. After initial conversations, “everyone has gone completely silent on this. They’re not saying no. They’re just not saying.”

Nelson said he will be raising money for a $100 million fund from the Middle East, a region he expects many of the startups in his portfolio will originate. Although he has ruled out backers from Russia (for legal and political reasons), Nelson says he’ll evaluate potentially limited partners on a case-by-case basis.

“It’s not an easy or clean answer. One of those things I have to evaluate is if I’m going to compromise myself and my values in doing this,” he said. “It would easy to say yes, and easy to say no. But the hard thing is to go step-by-step and do this thing morally and ethically.”

Most high profile firms in the tech industry may not have the luxury of selecting their shade of grey. Firms that decide to steer well clear of cash from repressive regimes could seize a clear advantage when competing for the best startups. Although unwinding past deals will be exceedingly hard to do, SoftBank may try to quarantine the $90 billion it’s taking from Saudi Arabia, and other venture firms could follow.

Next year’s due diligence question may become “Did you take Saudi money?” in the way inquiries into sexual harassment claims against venture partners’ were aimed at eliminating a clear business risk after the MeToo reckoning. For the best startups, with no shortage of suitors willing to write them a check, the cleanest hands may get the best deals.