Two of Seattle’s best known online real estate companies, Redfin and Zillow, have been hit with patent lawsuits by Chicago-based Earthcomber over the use of location-based technologies in their mobile applications.

Earthcomber gained notoriety in 2008 for suing influential technology news blog TechCrunch over a mobile patent that Michael Arrington called at the time “shaky.”

Earthcomber President Jim Brady told paidContent today that he is not a patent troll and that “big money bowls over small app makers like us.”

In a follow up email to GeekWire, Brady noted that he’s simply trying to protect the intellectual property that he created and built into his company’s products.

“The real missing angle is that all the big patent wars involve the giants, but what if you were the person with the vision and a dream and did all the work to make it happen before all this technology was so popular? That’s where Earthcomber is – the rare case of the original, practicing inventor standing up to companies that infringe,” he said.

Redfin's mobile app

A spokeswoman for Zillow said they have not yet been served with the suit, and added that they do not comment on pending litigation. We’ve asked Redfin for comment, and will update the post if we hear more.

Earthcomber also sued Dominion Enterprises, Trulia, Move, the National Association of Realtors, Network Communications, LoopNet, RealPage, Primedia and Ziprealty.

The patent at the heart of the lawsuits is U.S. patent 7,071,842, titled “System and Method for Locating and Notifying a User of  Person, Place or Thing Having Attributes Matching the User’s Stated Preferences.” Also in question is U.S. patent 7,589,628, which is titled “System and Method for Providing Location-Based Information to Mobile Consumers.”

Zillow’s mobile app is one of the most popular in the real estate category. The company said in September that Zillow was used on a mobile device more than 11 million times, with 2.4 million homes viewed on mobile devices each day – or 28 homes a second.

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