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merica's most popular real estate website, Zillow, is facing a new lawsuit from rival platform CoStar Group. CoStar claims that Zillow has used tens of thousands of its watermarked images without permission, which is the second major legal battle for Zillow this summer. The lawsuits raise questions about how much power a dominant digital portal can wield over residential real estate data and media.

    CoStar's lawsuit accuses Zillow of posting 46,979 copyrighted photos from CoStar Group's websites, including Apartments.com, LoopNet, and Homes.com, without permission. This has undermined CoStar Group's ability to stand out against competitors, particularly for rental units. "Zillow's theft of tens of thousands of CoStar Group's copyrighted photographs is nothing short of outrageous," said Andy Florance, CoStar Group's founder and CEO.

    Meanwhile, Compass filed an antitrust lawsuit against Zillow in June, alleging that its new listing policy restricts competition and harms consumers. The policy bans private home listings if they are marketed off-Zillow for more than one day. Zillow has denied engaging in anticompetitive tactics, saying it stands for transparency and equal access to information.

    The two lawsuits test the limits of platform control in housing and raise questions about whether a dominant digital portal can police distribution rules or display content without permission. If Compass prevails, Zillow may need to relax its rules that penalize off-platform marketing, increasing diversity in channels through which consumers find homes. A CoStar win could lead to tighter provenance controls and more robust license audits.

    The outcomes of these lawsuits will influence how Zillow operates and the digital architecture of U.S. homebuying and renting is organized. A win for Compass or CoStar would likely democratize access and strengthen IP compliance, while a clean sweep for Zillow would entrench the current gatekeeper model.