At Wednesday’s House Judiciary Committee hearing on the Stop Online Piracy Act (SOPA), opponents of the act avoided familiar claims that the legislation would “break the Internet.” But the hearing did highlight Internet companies‘ fears that the bill would undermine the Digital Millennium Copyright Act (DMCA), the law granting “safe harbor” protections against Internet services that allow users to upload content.

SOPA would allow content owners to obtain court orders requiring ISPs and search engines to block access to sites found to offer counterfeit goods and copyrighted content. The Senate Judiciary Committee passed a similar bill, PROTECT IP, in May. That bill has been blocked by Senator Ron Wyden (D – OR) and has not reached a vote in the full Senate.

Judiciary Committee Chairman Lamar Smith (R – TX21) said the U.S. “cannot continue a system that allows criminals to disregard our laws and import counterfeit and pirated goods across our physical borders,” according to a Dow Jones report on the hearing.

A few lawmakers voice concerns about SOPA. Representative Maxine Waters (D – CA35) said she is concerned the bill would give content owners the power to shut down sites that aren’t trafficking in illegal material. Representative Darrell Issa (D – CA49) said he won’t support the bill “in its current form.”

One primary concern of U.S.-based technology companies is SOPA‘s impact on the DMCA. Google’s copyright counsel, Katherine Oyama, said at the hearing that SOPA should be changed so companies such as Googlewon’t have to “proactively monitor all user-generated content in real time.”

While Google supports SOPA‘s stated goal of providing additional tools to fight foreign piracy, Oyama said, the company does not support the bill as it is written.

The day before the hearings, a number of leading Internet and technology companies wrote a letter to the chairmen and ranking members of the House and Senate judiciary committees that warn the proposed legislation would exposeU.S. companies to uncertain liabilities and jeopardize innovation and job creation. Among the letter signers were Google, Facebook, AOL, LinkedIn, Yahoo! and eBay.

Markham Erickson, executive director of Net Coalition, wrote in a piece at The Hill that both bills will, among other things, “gut” the DMCA. “The DMCA is one of the big reasons companies like Facebook, YouTube, and Twitter weren’t crushed in their early days by harassing lawsuits.”

But the Motion Picture Association of America counters that SOPA wouldn’t impact the likes of Facebook and Twitter. Michael P. O’Leary, the MPAA‘s senior executive vice president of global policy and external affairs, stated during the hearing that the bill is “narrowly defined” to target rogue sites and allows for “robust due process” and penalties for abuse. “Content owners that file frivolous or unsupported claims could face damages, including costs and attorneys’ fees,” he said.