As the world came to terms with the shock election of Donald Trump, India found itself dealing with its own systemic shock on Wednesday.

In a surprise move, Indian Prime Minister Narendra Modi announced that he was scrapping all current 500 and 1,000 rupee notes—rendering 86% of all Indian currency worthless, Bloomberg reports.

Banks around India were closed Wednesday in preparation for the switch, and ATMs were also turned off. Meanwhile, the country’s citizens panicked in the race to exchange their soon-to-be obsolete currency.

On the streets, massive lines snaked through India’s towns and cities on Thursday. There were reports of husbands discovering their wives’ secret stashes, saved quietly and carefully over decades. Many are now scrambling to rescue their life savings.

But Modi’s shock currency change was, in part, conceived to deter those stashing large amounts of money in order to avoid tax.

Since the Tuesday announcement, many in India have been asking Google for a solution to the problem of undisclosed wealth. Several iterations of “how to convert black money into white money” have been trending on Google, spiking sharply immediately after the announcement, with the most searchers in Gujarat—Modi’s home state. “‘Black money’ is the local term for cash stashed away to avoid tax,” Bloomberg reports.

The move is designed to bring all black money to the surface by “outing” tax evaders and preventing counterfeit 500 rupee notes.

“It is like a surgical strike on black money,” explained India’s Revenue Secretary Hasmukh Adhia, speaking to Reuters earlier in the week.

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“This one decision will change social culture, in the way people keep money and spend,” said India’s Finance Minister Arun Jaitley on Wednesday. “The honest person has the satisfaction to be honest and the not-so-honest worry.”