Twitter blocked tweets from verified accounts after a massive security breach

What do Joe Biden, Barack Obama, Elon Musk, and Bill Gates have in common?

Dozens of high-profile verified Twitter accounts were hacked on Wednesday, seemingly to push a cryptocurrency scam that may have netted upwards of $100,000 in a matter of minutes. These kinds of scams are old hat on Twitter, but never have so many prominent accounts been taken over at once.

To stem the tide, Twitter appeared to take the unprecedented step of suspending all tweets from verified accounts for about a half hour on Wednesday. They also blocked some password reset attempts. Other restrictions remained in place but largely unexplained through the evening.

Several victims of the hack said they use multi-factor authentication to protect their accounts, but that security feature was of no use. Instead, the sheer volume of hacked accounts suggests a problem with Twitter itself. A company spokesperson said Twitter is "investigating and taking steps" to address the incident. We don't know yet how it happened or who is behind the attack.

While the hack at first glance seemed to be part of a Bitcoin scam, there could be another motive. Any hacker who can tweet from an account could potentially be able to read private direct messages.

The incident has real-world impact: the National Weather Service was unable to tweet updates to thousands of followers as tornado warnings came into effect in Illinois.

The outcome could have been worse given the prominence of the victims. Perhaps the most infamous Twitter hack of all time took place in 2013, when the Associated Press tweeted about explosions at the White House and sent the stock market plummeting temporarily. The attackers this time around could have sown similar chaos. Last year, the account of Twitter founder Jack Dorsey was hacked.

The hacking of a presidential candidate and the potential breach of private communications echoes the 2016 race, when emails from Hillary Clinton's campaign and the Democratic National Committee were leaked by Russian government hackers. President Donald Trump, Twitter's most famous user, has not been affected by the incident.

Takeovers first began late in the afternoon US Eastern Time against primarily cryptocurrency-focused accounts like the trading platforms Coinbase, Gemini, and Binance. The impact spread quickly after that.