The U.S. Patent and Trademark Office in Alexandria, Va. (AP Photo/Alex Brandon)

A lot of groups are upset about so-called "patent trolls" -- companies that stockpile patents, then use them to get money out of other companies rather than actually make things with them.

These companies, also called "non-practicing entities," are on the rise. A PricewaterhouseCoopers study last year estimated that patent trolls are responsible for 67 percent of all patent lawsuits filed -- up from just 28 percent five years before.

They can target almost anyone. In 2012, hundreds of businesses received letters demanding $1,000 per employee for using scanners to send documents via e-mail.

[Patent trolls now account for 67 percent of all new patent lawsuits]

And earlier this year a "super-coalition," including big tech companies like Google and Facebook, as well as retailers like Macy's and restaurant and hotel trade groups, came together to support patent reform.

But Congress hasn't made much progress. Last year, one proposal called the Innovation Act made it through the House before being killed in the Senate, reportedly due to pressure from then-Senate Majority Leader Harry Reid (D-Nev.) that supporters said was due to the influence of trial lawyers.

With Republicans now in control of both chambers, patent reform may have a better shot. The 2015 version of the Innovation Act was already re-introduced in the House, and another proposal called the Targeting Rogue and Opaque Letters Act, or TROL Act, was marked up earlier this month by the House Energy & Commerce Committee.

And now, there's a bipartisan Senate proposal: The Protecting American Talent and Entrepreneurship Act, or "PATENT Act." The bill, announced Wednesday, is co-sponsored by Senate Judiciary Committee Chairman Chuck Grassley (R-Iowa) and ranking member Patrick Leahy (D-Vt.), along with a long list of fellow committee members: Sens. John Cornyn (R-Tex.)  and Chuck Schumer (D-N.Y.), Mike Lee (R- Utah), Orrin Hatch (R-Utah) and Amy Klobuchar (D-Minn.).

Many of the changes in the bill are aimed at making it more difficult for patent trolls to sue or extort companies, according to a summary released by the co-sponsors. The legislation, for example, would require patents trolls to provide more information about an alleged patent infringement in letters demanding payment.

"Based on what I've seen, there's a lot of needed reform here," said Vera Ranieri, a staff attorney for the Electronic Frontier Foundation, who has not yet been able to review the actual legislation. However, she said, it doesn't get at what the group considers the heart of the problem: The issuance of bad patents.

Despite a general consensus on many patent reform areas, progress has been slow partially because of the financial interests at stake, she said.

"First, there's a significant patent attorney bar that has a lot of interest in keeping the status quo," Ranieri said. But there are also the current owners of bad patents who don't want to lose them, she said, and companies that are interested in the expansion of intellectual property as a way to force out competition in their industries.

[Patent reform advocates are launching a ‘super-coalition’ to whack patent trolls]

However, Schumer is optimistic about the bill's chances. "We have assembled a really broad and politically diverse coalition -- and I think it's going to be the year that we finally pass patent reform," he told The Washington Post in an interview.

The tipping point, he said, is that patent trolls are now affecting "mainstream America," making the issue relevant to more Americans by hitting small businesses and retailers with lawsuits. "What's next, restaurants being sued for using spoons?" Schumer asked.