Facebook is auditing “tens of thousands” of apps that had access to users’ personal information, CEO Mark Zuckerberg testified Wednesday.

Zuckerberg said it’ll take “many months” to complete the audit, which was announced by Facebook last month.

“There are tens of thousands of apps that had large amounts of people’s information before we locked down the platform in 2014,” he said at the House Energy and Commerce Committee hearing.

He said if the apps are found to have misused users’ data, they’ll be banned from Facebook and forced to delete the information.

Answering a question from Rep. Jan Schakowsky about how many firms — besides Cambridge Analytica and Eunoia — had acquired data from psychologist Aleksandr Kogan, Zuckerberg said, “I don’t believe it was a large number, but as we complete the audits we will know more.”

“What’s a large number?” Schakowsky, a Democrat from Illinois, pressed.

“A handful,” Zuckerberg replied.