Razor, which is used to detect spam, has many different algorithms to find matches by accepting incoming spam from users who identify it as such. Now there's no reason you couldn't tweak it to work as a more generic tool. Say all the newspapers sent submissions to a letters-to-the-editor razor server. When several similar letters were recieved, Razor would notice the similarities and flag them as such.
The only thing you really need to do is get a large enough body of media submitting their frequently-boilerplated topics and check if they've been spotted before. You'd want to have a way to retrieve the other submissions so you could do an eyeball test, something not available in Razor right now, but the code could be extended to do this.
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The only thing you really need to do is get a large enough body of media submitting their frequently-boilerplated topics and check if they've been spotted before. You'd want to have a way to retrieve the other submissions so you could do an eyeball test, something not available in Razor right now, but the code could be extended to do this.