[irondavycole]

Promoting their own event is not without self-interest, even if the poster sales aren't directly profitable.

Also, it's not authorship over "red on white" as a concept, it's authorship over this specific combination of type, size, layout, & copy that implies association with Facebook. If they just wanted to maintain the message, and not the association, they wouldn't have kept the visual style. Implying an association (with Facebook, or Ben) that isn't really there is the dishonest part.

[catshirt]

no one, for all intents and purposes, would associate these signs with facebook.

[irondavycole]

And why wouldn't they? They're explicitly an homage to a photo that hundreds of thousands of people (especially those in the startup scene) saw.