Leahy praises administration officials for domain seizures

"In addition to the domain names that are seized through this operation, evidence suggests that the operation has a deterrent effect," Barnett said in his prepared remarks, noting that 81 of the most popular websites for pirated material voluntarily shut down after the first wave of seizures.

Espinel highlighted other examples of successful enforcement actions in her testimony, such as the seizure of $143 million in counterfeit Cisco hardware, but the domain seizures are of particular interest because of a bill passed unanimously by the committee last month that would likely widen the practice.

The PROTECT IP Act would make it easier for the Justice Department to seize domain names, raising concerns among some critics that the bill would lead to government censorship of the Web.

Sen. Ron Wyden (D-Ore.) placed a hold on the bill last month while negotiations take place over narrowing the authorities conveyed by the legislation.