If you have an American Express account and you tried to check your balance or see your statement yesterday, you may have been confronted with a blank screen, or some strange, ancient typeface.
It wasn't just you. American Express confirmed yesterday that its website was the latest target of major cyber attacks.
Other recent victims include JP-Morgan Chase, Wells Fargo, and Bank of America.
A group that calls itself Izz ad-Din al-Qassam Cyber Fighters has claimed responsibility for those attacks.
And they seem to be aiming to destroy these websites and companies, not just temporarily disrupt their service. That could be a sign of a far more troubling trend in cyber warfare, especially if these hackers are backed by state governments.
David Sanger is the chief Washington correspondent for The New York Times.