Greg Sandoval/CNET

The U.S. Department of Homeland Security is seizing domains and taking down URLs in the name of copyright infringement, but its tactics are worrying certain members of Congress.

In a letter (pdf) sent last week to Attorney General Eric Holder and Secretary Janet Napolitano, three members of the House Judiciary Committee aired their unease.

"We are concerned about your Departments' seizure of domain names under Operation In Our Sites, launched in November 2010," the letter said. "Our concern centers on your Department's methods, and the process given, when seizing the domain names of websites whose actions and content are presumed to be lawful, protected speech."

The three Congress members -- Rep. Zoe Lofgren, Rep. Jared Polis -- and Rep. Jason Chaffetz, point to one case that exemplifies a situation where Homeland Security got it wrong. Over a year ago, the government took down a hip-hop Web site owned by a man who goes by Dajaz1 on the basis that it linked to copyrighted songs. However, the links didn't actually infringe on copyrights.

"Much of Dajaz1's information was lawful, and many of the allegedly infringing links to copyrighted songs, and specifically the links that were the basis of the seizure order, were given to the site's owner by artists and labels themselves," the Congress members wrote in the letter.

Apparently the government refused to cooperate with Dajaz1's lawyers and worked with the Recording Industry Association of America (RIAA) to keep the Web site down longer than necessary. After one year, Homeland Security handed Dajaz1 back his Web site without any explanation.

According to the Electronic Frontier Foundation, a similar situation happened with the Rojadirecta.com and Rojadirecta.org sports streaming sites.

In February, the feds boasted a major takedown of over a dozen Web sites that allegedly live-streamed copyrighted sporting events. Dubbed Operation Fake Sweep, these seizures were part of the "Operation In Our Sites" initiative.

According to the U.S. Immigration and Customs Enforcement, roughly 700 domain names have been seized since "Operation In Our Sites" launched in 2010.