Some security experts said at the time that they might not even be attacks, but simply internal technical problems, similar to what shut down GoDaddy recently. Or, that they might simply be low-level attacks by anti-capitalist groups with a political agenda.

And even now there is not unanimous agreement that Izz al-Din al-Qassam Cyber Fighters is behind all the attacks. The group has not made good on all of its threats. It had also said it would attack the New York Stock Exchange, but trading has continued normally there.

Dmitri Alperovitch, chief executive of CrowdStrike, a private security firm investigating the attacks, that the claims "appear to be accurate in terms of predicting future attacks. But I wouldn't necessarily take at face value any of its claims about attribution or the video."

Whatever their source, the attacks have prompted some renewed calls for more coordination between the private sector and government, which was the goal of the 2012 Cyber Security Act (CSA) that .

But so far, they have not been even close to catastrophic, partially because, as a number of security experts have noted, DoS attacks are among the oldest and most basic, and do not require highly skilled computer programmers or advanced expertise.