Michelle Malkin reported that there was a DOS attack Hosting Matters that brought several popular blogs off line:

Today, 11:46 AM This morning at approximately 10:00 AM Eastern time, we noted a sudden abnormal surge in traffic to the network.
Shortly thereafter, our upstreams confirmed that one of the servers within the network was the target of a massive DOS attack.
We worked with the NOC and the upstreams to further identify the target and steps were taken to isolate that target from the rest of the network.
Recovery on all segments except that target segment is complete. The target of the attack will not be brought back online and will be removed from the main network in the event they are the target of future attacks, so as not to negatively impact other clients.
We are currently working to address clients who may be on that same segment of the network to bring them back online.
Stacy – Hosting Matters, Inc.

There was a second attack last night:

We are seeing another round of attacks after changing the IPs on the target server. This is an indication that the target from earlier either was not the primary target or was a byproduct of the original attack and identified as the primary target.
Working on this now with the NOC and upstreams.

The source of the attacks? Saudia Arabia. The reason? Political cartoons (this is what they think at this time ).
Free speech baby, get used to it. This is what it means to be free, we get to say what you don’t want to hear. And Americans will just say it louder and more viciously when you try to shut them down.
Read further updates here.