Posting on his blog, Deupree -- also known as 12K -- called U2's cover "nearly an exact rip-off" of his and Chartier's Specification.Fifteen, released in 2006. That album was commissioned by the Hirschhorn Museum in Washington, D.C., in honour of a Sugimoto retrospective, and was performed at the opening of the exhibition. The CD was released in a (sold out) run of 1,000.

Of course, the cover to No Line On the Horizon isn't just a Sugimoto seascape -- there's a mysterious white equals sign as well. Alas, that too recalls the design of Brothomstates's Claro album cover. The album, released by Warp Records in 2001, doesn't have an equals sign -- but it does have a mysterious white square.

Though Brothomstates haven't commented on the similarity, Deupree's online comments take a relatively pragmatic stance. He admitted that his soundscapes haven't penetrated the mainstream, writing that "perhaps if our CD was available to a wider audience, U2's graphic designer would have been aware of it and attempted something a bit different."

He emphasised the difference between the two groups. Whereas he and Chartier were invited and endorsed by Hiroshi Sugimoto -- and permitted to use his photograph for free -- for U2 "it's simply a phone call and a cheque."

"Naturally, when something we have slaved over, fought for recognition over, is so easily undone by pop culture, it feels a bit cheap," he wrote. What for us is one of the greatest achievements in a career thus far is simply a phone call for U2."

"Before you let people run off about how 'cool' the new U2 cover is...show them ours first."

© 2009 Guardian.