Musk’s Twitter account posted multiple messages on Wednesday promising to “double” payments to his bitcoin address, also known as a BTC address.

Biden’s and Gates’ account posted a similar message, telling followers: “If you send $1,000, I will send back $2,000.”

Bezos’ account also vowed to double payments sent to his BTC address. “I am only doing a maximum of $50,000,000,” a tweet on the Amazon founder’s account said.

An identical BTC address was posted to all three accounts.

As BuzzFeed tech reporter Ryan Mac noted, the posted BTC address did appear to be receiving bitcoin on Wednesday but said it was hard to say whether those transactions were being seeded by the scammers themselves or being sent by people who may have been duped.

“This goes without saying, but do not send the account money,” Mac warned.

The New York Times said at least $100,000 had already been stolen as part of the scheme.

CNBC reported that similar tweets promising a doubled return had appeared on the verified accounts of several major tech companies, including Apple, Uber and Cash App. Rapper and producer Kanye West and former New York City Michael Bloomberg also appear to have been targets.

Twitter said in a statement that it was “aware of a security incident impacting accounts” on its platform.

“We are investigating and taking steps to fix it,” it said.