Skullphone image inserted into ClearChannel digital billboard ads (Not a hack, but paid for?)

 Wp-Content Uploads Skullphone

UPDATE: Wired's Threat Level called ClearChannel, who said the Skullphone is not a hack, but a paid ad.

Laughing Squid reports: "An entity simply known as Skullphone has been altering Clear Channel digital billboards in Los Angeles, by hacking into the computer that runs the billboard and inserting the Skullphone image between the ads." Link