Angry Business Owner Wages War on 'Troll' Kevin O'Connor, who co-founded ad tech company Doubleclick, is publicly battling a patent troll who is demanding $50,000.

One entrepreneur is mad as hell. And he isn't gonna take it anymore.

Doubleclick co-founder and FindTheBest chief executive Kevin O'Connor is taking the rare step of waging a war on a patent troll.

Patent trolls are the bane of many entrepreneurs. They make it a business of suing startups and other businesses for infringing upon patents they own in return for licensing fees. Essentially they aren't really businesses themselves, but holding companies that own one or a portfolio of patents that they simply enforce. Translation: the troll does nothing with his or her patents except for suing companies that allegedly infringe upon them. The patents can be somewhat vague and sometimes be for functions or features that are very common in other products.

The threat of patent trolls is growing -- especially among software companies. A report last month from the U.S. Government Accountability Office found that between 2007 and 2011 the "number of overall defendants in patent infringement lawsuits increased by about 129 percent." What's more, 89 percent of the increase in defendants over this period was from lawsuits regarding patents on software.

Related: The FTC Recommends Sweeping Investigation of Patent Trolls

Enough to get you fired up, right? In O'Connor's case, FindTheBest was notified that it is being sued for $50,000 over a patent for a "system and method for facilitating bilateral and multilateral decision-making." Whatever that means. In July, O'Connor penned an article on tech site PandoDaily about how he planned to "slaughter" the troll, otherwise referred to as the "scum of the earth." O'Connor, who sold DoubleClick to Google in 2008 for $3.1 billion, has ponied up $1 million of his own money to battle the so-called troll in court.

It's only the third time a major effort has been mounted to fight a patent troll under the Racketeer Influenced Corrupt Organizations (RICO) act, a report from Ars Technica says. "From a business perspective, it makes 100 percent sense to settle," O'Connor said in the article. "I decided to take it out of the business realm, and into the personal. There's one thing I love and that's technology, and there's one thing I hate, and that's injustice -- people abusing the system."

O'Connor, of course, is far from alone in his distaste for so-called patent trolls. Billionaire tech entrepreneur and Dallas Mavericks owner Mark Cuban has spoken out numerous times about patent trolls and about how he thinks the patent system in general is broken. In February, Cuban and Reddit co-founder Alexis Ohanian teamed up with the Electronic Frontier Foundation (EFF) and Engine Advocacy to officially request that Congress investigate patent trolls in order to stop the surge in "patent lawsuit abuse."

Related: Patent Trolls Hit With a One-Two Punch

Late last year, Cuban and Markus Persson, creator of the Minecraft game, donated a combined $500,000 to the EFF. Cuban's $250,000 donation went toward hiring a new patent litigation lawyer and funded a new title at the organization called "The Mark Cuban Chair to Eliminate Stupid Patents."

It doesn't get any more real than that.