EXPLAINER: Why Twitter's former security head is testifying

Peiter Zatko, the former Twitter security chief who’s accused the company of negligence with privacy and security in a whistleblower complaint, will testify before Congress on Tuesday.

Zatko is well-respected in the cybersecurity space, which gives his complaints extra weight. But so far he has little documentary support for his claims — unlike the Facebook whistleblower, Frances Haugen, whose complaint last year included troves of internal documents from the company now called Meta.

Zatko’s accusations are also playing into Tesla CEO Elon Musk’s battle with Twitter to get out of his $44 billion bid to buy the company. The Delaware judge overseeing that case has ruled that Musk can include new evidence related to Zatko’s allegations in the high-stakes trial set to start Oct. 17.