Israeli cybersecurity firm Hudson Rock considers the threat to be credible and believes sensitive information (including usernames, emails and phone numbers) could be leaked onto the dark web.
Among the first names reported by the hacker are those of US Democrat Alexandria Ocasio-Cortez, security expert Brian Krebs, actor Salman Khan, Google CEO Sundar Pichai and Donald Trump.
A new headache for Elon Musk? Twitter could be fined hugely by the GDPR for failing to protect information that should never have left Twitter's premises."/>