The Saudi hacker who managed to steal 15 thousand Israeli credit cards revealed another 11 thousand stolen numbers on Thursday, and threatened to release one million total stolen numbers.

According to a message left on the Saudi hacking group Group-XP’s message board, the hacker, who goes by the name of 0xOmar, was able to hack “much more than one can imagine.”

Credit card companies have announced that they have a list of all hacked numbers, and are currently enlisting teams to assess the situation and update cardholders. According to the companies, only a few tens of thousands of newly-issued cards were hacked, and were cancelled before any transactions were carried out.

The hacker’s message comes several after he was able to penetrate one of Israel's leading sports websites and released the personal information of hundreds of thousands of Israelis.

In the message, the hacker wrote that Group-XP found the idea of “400 thousand people crowding Israeli credit card companies and banks and complaining their credit card details were stolen, watching as Israeli banks shredding 400 thousand credit cards and issuing new ones,” was appealing.

The website, One, said they were looking into the issue, and shortly after the page was hacked it returned to normal activity.