The exception in the act now that provides the 30-day limit says that for broadcasting purposes, radio stations can make temporary copies, and they can keep them for 30 days or less. They have to destroy them after 30 days, unless they're willing to pay the licence fee for them. As long as those copies are temporary copies for broadcasting purposes, they can keep those copies for 30 days.
On March 12th, 2012. See this statement in context.