An unknown but higher proportion of the era's blockbusters, the full-length feature films, survive. Some are readily available, and some are available only with difficulty in secondhand versions. Many languish unseen in studio vaults, in the holdings of amateur and professional archivists and at the Library of Congress.

Even Harold Lloyd's "Safety Last," which has the iconic scene of the hero dangling from a clock--probably the most famous image from the silent era--is generally unavailable.

So are Michael Curtiz's "Noah's Ark" and Clarence Brown's Klondike tale "The Trail of '98," both epics that were the "Titanic" of their day. Capra's "Power of the Press," starring Douglas Fairbanks Jr. as a cub newspaper reporter, also is highly regarded but extremely difficult, if not impossible, to see.

The motion picture association's brief takes direct aim at Agee's assertions, saying it instead will "offer the Court a real-world perspective."

First of all, the brief says, the industry is doing all it can to preserve what still can be preserved.

"Studios have started to devote millions of dollars each year to preservation and restoration," the MPAA says.

One acknowledged role of copyright is to act as incentive: The creator of a successful work enjoys certain benefits, usually financial, that inspire someone else to create. But if the studios don't own the original works, the MPAA brief argues, they probably won't be able to produce derivative works such as anniversary editions.

An example cited in the brief is Warner Bros.' 50th anniversary edition of Orson Welles' "Citizen Kane," which is not only restored but includes newsreel footage of the premiere and running commentary by director Peter Bogdanovich and critic Roger Ebert. Nor would Warner Bros. spend $350,000 to restore "Casablanca" if it didn't own it, the motion picture association says. (To reacquaint the justices with these classics, the MPAA sent DVDs to the court.)

"Petitioners," the brief notes, "may take issue with this logic."

Boy, does he. The camera negative of "Citizen Kane" was rendered for its silver content in the mid-1970s, Agee said. It's only because a Library of Congress vault custodian made a copy that Warner Bros. had first-generation material to restore.

"The brief conveniently fails to note that all of these classic studio films which have supposedly been preserved have mainly been preserved at the taxpayer's expense by the Library and the American Film Institute," Agee said.