A number of high-profile Twitter  accounts were simultaneously hacked on Wednesday by attackers who used the accounts — some with millions of followers — to spread a cryptocurrency scam.

Billionaires Elon Musk, Jeff Bezos and Bill Gates are among many prominent US figures targeted by hackers on Twitter in an apparent Bitcoin scam. The official accounts of Barack Obama, Joe Biden and Kanye West also requested donations in the cryptocurrency.

“Everyone is asking me to give back,” a tweet from Joe Biden’s account said. “You send $1,000, I send you back $2,000.”

“Tough day for us at Twitter. We all feel terrible this happened,” tweeted CEO Jack Dorsey late on Wednesday. “We’re diagnosing and will share everything we can when we have a more complete understanding of exactly what happened,” said Mr Dorsey.

In the hours following the initial scam posts, Kim Kardashian West, Jeff Bezos, Bill Gates, Barack Obama, Wiz Khalifa, Warren Buffett, YouTuber MrBeast, Wendy’s, Uber, CashApp and Mike Bloomberg also posted the cryptocurrency scam.

Twitter will likely spend the next several days investigating how this incident took place. A criminal investigation seems likely, during which the company may not be able to fully describe Wednesday’s events to our satisfaction.

But it is vital that as soon as possible, Twitter share as much about what happened today as it can — and, just as importantly, what it will do to ensure that it never happens again.