McCann Erickson Ireland accused of copyright infringement

Sonarstate has threatened legal action against Heineken and global ad agency McCann Erickson for alleged copyright infringement in their ‘Where's your head at?’ campaign. (Not related to the Australian Where's your head at anti drug campaign.)
Sonarstate claims the Speakerboy character they use has been nicked by Heineken and turned into a Speakerhead character, Sonarstate claims it's plagiarised.
Sonarstates own speakerboy - not connected to the loud speaker builders located at speakerboy.org - can be seen in small speakerboy films here.

A quote from the Sunday Business Post Online reveals more

However, a posting on an Irish creative design website last week, attributed to one of the design team behind the Heineken campaign, said that it was unaware of the existence of the Speakerboy character, while developing the character. The person also said that there had been no deliberate attempts to copy the concept.

The web posting said that similarities between the two characters had been an “unfortunate coincidence'‘.