With physical CD sales dwindling, you don't hear as much about how certain records aren't carried by particular retailers due to so-called "objectionable content." But it still happens. Case-in-point: the new album from pop-punk lifers Green Day, whose latest disc, 21st Century Breakdown, cannot be found at Wal-Mart.

Remember, before being overtaken by Apple's iTunes, the brick-and-mortar megastore was the country's largest seller of recorded music. Yet with floor space dedicated to CDs shrinking and online outlets (legal and otherwise) proliferating, does it even matter that the Number One album in America can't be purchased alongside a six-pack of Brawndo and a hunting rifle? Green Day frontman Billie Joe Armstrong thinks so: "Wal-Mart's become the biggest retail outlet in the country, but they won't carry our record because they wanted us to censor it," he said in a recent interview.

Read more in this Comcast.net feature (Comcast actually has a promotion going with Green Day via its On-Demand service -- talk about a clash of the corporate titans).

Wal-Mart carries a "clean" version of Eminem's grisly latest, but Armstrong claims "there's nothing dirty about our record." Is this censorship? Tell us what you think in the comments.