The third unnamed person is reportedly a US citizen while the two former employees are said to US Saudi citizens. It has also been reported that they spied on behalf of the government in Riyadh. According to a prosecutors statement mentioned in the court filing, the three persons worked for a entity named "Royal Family Member-1".
According to The Washington Post, this was Saudi Crown Prince Mohammed bin Salman.
"The criminal complaint unsealed today alleges that Saudi agents mined Twitter's internal systems for personal information about known Saudi critics and thousands of other Twitter users," said US Attorney David Anderson.
"US law protects US companies from such an unlawful foreign intrusion. We will not allow US companies or US technology to become tools of foreign repression in violation of US law," Anderson was quoted as saying in a statement.
The latest lawsuit comes on the heels of the killing of Saudi journalist Jamal Khashoggi who was dismembered at the Saudi consulate in Istanbul. Khashoggi's death according to the Post had been Riyadh-sanctioned and has continued to strain US-Saudi relations.