Google co-founder Sergey Brin slammed the proposed billionaire tax in California, likening it to the socialism that he fled with his family from the former Soviet Union.

Brin is one of the billionaires who relocated out of the Golden State to avoid the potential wealth tax that's expected to appear on California voters' ballots this fall. The proposal would impose a one-time 5% tax on residents whose net worth exceeds $1 billion. 

Assets covered by the tax may include businesses, securities, art, collectibles, and intellectual property – though real property, pensions and certain retirement accounts would be exempt.

"I fled socialism with my family in 1979 and know the devastating, oppressive society it created in the Soviet Union. I don't want California to end up in the same place," Brin said in a statement to The New York Times regarding a story by the outlet that discussed his move.

The proposed wealth tax applies retroactively to Californians who were residents of the state at the start of 2026, which prompted Brin to move out of the state late last year.

The Times reported, citing a person familiar with the arrangement, that Brin moved to the Nevada side of Lake Tahoe and is spending every other week at Google's headquarters in California.

Brin's opposition to the wealth tax on billionaires prompted him to work with other like-minded Californians and build support for an effort to defeat the measure.

The Times reported that Brin formed a pair of nonprofit groups as part of his political engagement around the wealth tax proposal, putting $57 million into Building a Better California over the last four months.