Nobody doubts the United States is in need of reforming copyright law.

Register of Copyrights Maria Pallante told a House congressional subcommittee Wednesday that everything from anticircumvention provisions and fair use to length of copyright and performance royalties should be on the table.

The hearing comes a month after the White House announced publicly that Americans should be able to unlock their mobile phones and use them with any compatible carrier they choose. The announcement was in response to a Copyright Office directive that mobile-phone unlockers could be subject to criminal or civil penalties – which prompted a massive public outcry that reforming copyright law was long overdue.

But any change to the copyright regime is likely to come at a snail's pace, Pallante, the head of the Copyright Office, told the House Subcommittee on Courts, Intellectual Property and the Internet as she discussed what she termed the "Next Great Copyright Act."

"A few years of solid drafting and revision is what you're really looking at if you want to do something," she said.

Among other things, she suggested bolstering criminal penalties for copyright infringement.

"Exclusive rights will just not be meaningful if there is no way to enforce them," she said.

The last time Congress dealt with copyright was in 1998, when it passed the Digital Millennium Copyright Act.

Blogs, search engines, e-commerce sites, video and social-networking portals are thriving today in large part due to the notice-and-takedown regime ushered in by the much-maligned copyright overhaul. When the DMCA was enacted, these innovations were unheard of, embryonic or not yet conceived. Now, Google has grown into one of the world's largest companies, and its video-sharing site YouTube has left an enduring mark on public discourse.

The DMCA's notice-and-takedown provision grants immunity to so-called "intermediaries" – ISPs, for example – for any copyright infringement by their users. To earn that "safe harbor," the intermediary (such as video-sharing site YouTube) must promptly remove material if the copyright holder sends a takedown notice.

But there are also some downsides to the law. It dictates that "no person shall circumvent a technological measure that effectively controls access to a work protected under this title" – language that, for example, blocks a DVD owner from legally copying a disc they have lawfully purchased or a cellphone owner from altering software that dictates a phone's carrier.

"You should look at the efficacy of the DMCA," Pallante said.

Then there's the Copyright Act of 1976, the other main copyright law in the United States. Among other things, it allows for fines of up to $150,000 per violation, such as sharing a copyright-protected song on a peer-to-peer network.

None of the lawmakers suggested that the fines were too big. And the Supreme Court on Monday let stand a $220,000 jury verdict against infamous file-sharer Jammie Thomas of Minnesota, who the Recording Industry Association of America sued for illegally sharing 24 songs.

While Pallante was not suggesting that file sharing should be legal, she said there may be instances in which making copies of protected works should be authorized under a concept known as "fair use."

"Not every reproduction," she said, "is a reproduction with a capital R."