The process is this: Corporations, trade associations, governments, individuals and tons of other groups write up press releases about themselves. Then they send those to journalists. Then journalists put them into their publications. Then you, the reader, catches them and quits reading crappy journalism.
That's the concept behind a new search tool created by The Sunlight Foundation. Called "Churnalism," the search tool allows users to paste text or a URL in and find out whether the text was drawn from another news source or a press release.
Thus far, it looks like Churnalism doesn't have a very large database of press releases and other news sources. But one of its top-viewed results, seen here, illustrates how it can catch full quotes and phrases in a news source that appeared in a press release.