It’s no secret that tech bros love universal basic income. Sam Altman of Y Combinator is funding a UBI pilot program in Oakland, California, in part because he was inspired by Star Trek. Tesla’s Elon Musk supports the policy because he realizes that the aggressive automation caused by the tech industry will make UBI “necessary.” This week, as part of his “I’m-not-running-for-president” tour around the country, Mark Zuckerberg visited Homer, Alaska, which resulted in him writing a Facebook post lauding the merits of the state’s Permanent Fund as a model for a national form of basic income.

UBI, a concept that dates back centuries, is the idea that every person should receive some amount of money so that no one dips beneath a basic standard of living. For those on the left, it’s seen as an alternative to our country’s woefully limited cash welfare system. For libertarians, a basic income is lauded as a slimmer, less intrusive way to deliver government benefits. It is the rare utopian idea that people of different political stripes can agree on—Zuckerberg himself made sure to note the “bipartisan” appeal of the policy in his post.

But Zuckerberg reveals exactly why the left should be alarmed that Silicon Valley is taking the lead on this issue.

First, the idea that UBI has bipartisan appeal is disingenuous. The left would have a policy that redistributes wealth by funding UBI through a more progressive tax scheme or the diverting of capital income. But libertarians like Charles Murray argue for a UBI that completely scraps our existing welfare state, including programs like Medicare, Medicaid, and housing subsidies. This would be extremely regressive, since money currently directed towards the poor would instead be spread out for a basic income for all. And certain benefits like health insurance can’t effectively be replaced with cash.

Zuckerberg’s advocacy of UBI “bipartisanship” starts to look more like a veiled libertarian agenda.

Second, Zuckerberg asserts that Alaska’s Permanent Fund—which uses the state’s oil resources to pay a dividend to each Alaskan and is seen as one of the few examples of an actual UBI-like policy—is advantageous because it “comes from conservative principles of smaller government, rather than progressive principles of a larger safety net.” But a UBI policy can only reflect small government principles if one envisions it eating into the country’s existing welfare state, rather than coming on top of it. In this respect, Zuckerberg’s advocacy of UBI “bipartisanship” starts to look more like a veiled libertarian agenda.