The world's largest patent-holding company, Intellectual Ventures (IV), has opened up a Washington DC office, according to The Washington Post's Capital Business blog. The move appears to be a ramping up of the company's lobbying efforts in a year in which "patent trolls" have come under unprecedented criticism in Congress.

For each of the past four years, Congressional lobbying records show that IV has spent about $1 million annually advocating to lawmakers in areas like patent policy and litigation reform. In 2007 and 2008, it spent around $900,000. Back in 2005, it spent $440,000.

The firm was founded over a decade ago by former Microsoft executive Nathan Myhrvold. It spent years acquiring tens of thousands of patents before it began filing court cases in 2009.

The head of the new office, Russell Merbeth, explained that IV isn't engaging in some of the patent attacks on small businesses or end-users that have lawmakers so concerned.

"If Congress wants to enact something to reform that without needlessly undermining the value of patents at large, we’re in support of that,” he said. “When we do wind up suing a company for infringement, these are large multinational corporations with hundreds of millions if not billions in annual revenue, distinguishing [IV] from some of the companies and behavior that people are complaining about."

IV is a growing firm. It told the Post that it now employs 800 people in 11 offices around the world and has purchased more than 70,000 patents. (It's important to note that IV includes non-US patents when it comes up with those huge five-figure numbers on its patent holdings.)

IV reports it has filed "about 25" lawsuits, but that doesn't count the many cases it has filed through shell companies. One IV-connected shell company that became high profile is Oasis Research, a company highlighted in two This American Life programs called "When Patents Attack."

This summer, IV sued a slew of large financial institutions for infringing various patents, including HSBC Bank, JP Morgan Chase, Capital One, and Bank of America.