Is this plagiarism? A new web extension can help answer that question

Suspicious about the origins of an article you’re reading online? A new browser extension and website, Churnalism U.S., claims to help detect plagiarism by comparing web content to Wikipedia and a database of press releases.

Churnalism was built by the Sunlight Foundation, a Washington, DC-based nonprofit that aims to make government more transparent and accountable, and Media Standards Trust, a U.K.-based nonprofit that advocates for transparency in news. The organizations previously created a U.K. version of Churnalism that compares web content to articles from the U.K. national press and the BBC.

“Here at Sunlight, we’re increasingly interested in tracking not just the flow of money in politics, but the flow of ideas, whether in legislation or floor speeches or news articles,” Sunlight Labs director Tom Lee said in a statement. “When we learned of what Media Standards Trust developed, it seemed natural for us to help them bring it to the U.S. news consumer.”

Churnalism U.S. is available as a web extension for Chrome (s GOOG), Mozilla Firefox and Internet Explorer (s MSFT) browsers, or users can simply paste a URL into a website. The service then highlights possible similarities between the article and source material from Wikipedia and press releases. On its blog, Churnalism explains a little more about how the technology works to detect plagiarism. The database of press releases includes PRNewsWire, PR NewsWeb, MarketWire, EurekaAlert, Congressional Leadership and press releases from the White House, trade organizations, Fortune 500 companies and nonprofit research institutes and think tanks.

Because Churnalism U.S. is only searching Wikipedia and press releases, it doesn’t detect “classic” forms of plagiarism — an author copying another author’s original content from somewhere else on the web or in a printed work. Churnalism doesn’t pick up (yes, I checked) Atlantic writer Nate Thayer’s failure to credit his sources, for example, or Jonah Lehrer’s self-borrowing. For that, you’ll have to use a paid tool like Turn It In. But Churnalism plans to open up its API soon so that users can add more sources.