A group of lawsuits filed yesterday by Priceline founder Walker Digital take aim at Apple, Google, Microsoft, Amazon, and more than 100 other companies for infringing on key parts of its patent portfolio.

The 15 lawsuits, filed in U.S. District Court of Delaware, say these companies are infringing Walker Digital-owned patents covering things like e-commerce, private social-networking communications, online auctions, and a driving directions tool with visual cues.

"A number of great companies can trace their genesis to technology that was first developed at Walker Digital in the mid-to-late 1990s," Walker Digital's Chairman Jay Walker said in a statement. "We are proud of our inventions and the number of innovative businesses and activities founded on these inventions. These businesses have not only changed the way people around the world live, work, travel and interact socially and commercially, but also have given rise to numerous American jobs."

Walker Digital is the founder of Priceline.com, and has more than 200 U.S. patents as part of its intellectual property portfolio. Chairman Walker is named on more than 450 issued and pending U.S. and international patents, the company said in its suits. Through its IP licensing business, the company says it generates more than $200 million in licensing revenue from these patents.

In its statement about the wave of suits, Walker Digital's CEO Jon Ellenthal said the move had come after negotiations with companies over establishing a licensing deal had fallen through.

"Filing these lawsuits is not a step we sought or preferred," Ellenthal said. "We have reached out to a wide range of companies that are engaging in commercial activities that clearly depend on inventions created and owned by Walker Digital. Unfortunately, many of these companies have refused to engage in meaningful negotiations that acknowledge the market value they derive from the use of our property."

As part of the suits, Walker Digital announced it's teamed up with the IP Navigation Group, which will serve as the company's IP advisor. Together, the group seeks to "realize a fair return on the use of our property," Walker said.

Back in January, Walker Digital targeted social-gaming company Zynga and gaming giant Activision Blizzard for infringing on its "Database driven online distributed tournament system" patent. Just months before, it had sued Facebook for its friending mechanism, saying the longstanding feature was infringing on its patent for "establishing and maintaining user-controlled anonymous communications." Facebook is once again named in this latest wave of lawsuits, alongside Amazon, Fandango, Expedia and others for doling out bonuses for online shoppers.

The news comes at a time when intellectual property litigation is an increasing threat among tech companies. Just last week, Google announced it bid $900 million in an effort to acquire Nortel's 6,000 some patent portfolio. That move, the company said, was to serve as defense against patent litigation. Meanwhile, pending regulatory hurdles, Novell's 882 patents, which went on the market as part of a sale to CPTN Holdings LLC late last year, will be split up between Microsoft, Apple, Oracle, EMC, and Novell's parent company Attachmate, giving each of the companies a greater IP war chest.

Last month the U.S. Senate passed legislation for restructuring the country's patent system, changing the filing rights system to a "first to file" system, as well as giving the office power to set its own funding. Technology companies like Microsoft, which is once again at legal odds against I4i in a $200 million patent-related suit, had pushed for the reform, saying it would bring the U.S. up to speed with patent efforts abroad.

Correction at 12:46 p.m. PT: A reference to IP technology was mistakenly spelled out during the editing process as Internet Protocol. In this reference, it stands for intellectual property.