Twitter's former security chief Peiter "Mudge" Zatko accused the company of misleading the public, the government and its own board of directors over security flaws.

The social media company said the billionaire Tesla CEO changed his mind about accepting a board seat after becoming Twitter's biggest shareholder.

A software engineer known to few outside Twitter has replaced the company's eccentric co-founder Jack Dorsey, famous for his long beard, love of meditation and bitcoin.