Personalized Internet radio service Pandora is, again, threatening to shutter the service in the wake of new licensing fees due SoundExchange, under the recent Copyright Royalty Board licensing system.

Founder Tim Westergren tells the Washington Post that the lack of action among Washington lawmakers to revise the payments through some kind of deal between Webcasters and SoundExchange may force him to shut down the service. Under current rules he would need to pay 70% of his projected $25 million in revenues just for licensing.

The threat is not a new one. Westergren has been a vocal opponent to the new rates since the beginning. Pandora already has silenced service outside of the U.S., and told Billboard in May that a renewed legislative and PR push was imminent.

Pandora recently created a version of the service for the iPhone, which quickly became one of the most popular music applications available via Apple's new App Store.