The Protect IP Act, which would allow the U.S. Department of Justice to seek court orders focused on shutting down websites accused of copyright infringement, could come up for a vote in the U.S. Senate by early December, and one senator is threatening to filibuster the bill.

Senator Ron Wyden, an Oregon Democrat, has talked about a filibuster, with the bill likely to come before the full Senate in the next few weeks. During a filibuster, a senator continues to speak on the Senate floor, preventing the Senate from moving forward on a piece of legislation.

It's unclear whether Wyden could rally the 41 votes he would need to maintain the filibuster if backers of Protect IP called for a cloture vote. Forty of the 100 senators are sponsors of the legislation, which would allow the U.S. Department of Justice to seek court orders requiring search engines and Internet service providers to stop sending traffic to websites accused of infringing copyright.

The Senate Judiciary Committee unanimously voted to approve Protect IP, also known as PIPA or the Preventing Real Online Threats to Economic Creativity and Theft of Intellectual Property Act, in late May, two weeks after it was introduced.

Wyden, working with liberal activist group Demand Progress, has asked opponents of Protect IP to sign their names at StopCensorship.org, with the plan to read the names of opponents during a filibuster. In the first 24 hours after Wyden's request, more than 50,000 people had signed their names, according to Demand Progress.

Protect IP and the Stop Online Piracy Act (SOPA), a similar piece of legislation in the U.S. House of Representatives, would do "lasting damage" to the Internet, Wyden said in a video posted on StopCensorship.org.

"The at-all-cost approaches that these bills take to protecting intellectual property sacrifices cybersecurity while restricting free speech and innovation," he added. "Congress needs to hear from more than the lobbyists who helped write these bills. Congress needs to hear from people like you, who understand the value of a fair and free Internet."

In addition to the DOJ requests for court orders, Protect IP would also allow copyright holders to seek court orders requiring payment processors and online ad networks to stop doing business with allegedly infringing websites. Opponents of the bill say it could lead to legitimate websites targeted by copyright holders and could create online security problems as Web users circumvent blocks by ISPs and search engines.

Senator Patrick Leahy, a Vermont Democrat and lead sponsor of Protect IP, discounted opposition to the bill. Leahy and other supporters of the legislation say it's needed to combat online piracy and counterfeit websites operating overseas.

"The Protect IP Act is sponsored by 40 Senators on both sides of the aisle -- few pieces of legislation can boast that kind of bipartisan support," he said in a statement. "I expect that support will continue to grow when the majority leader schedules floor consideration of this important bill, which will promote America's economy and protect American consumers."

Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's e-mail address is grant_gross@idg.com.