Matt Buchanan publishes a list of the news websites that have the most stories that go viral on Facebook (getting at least 100 "interactions"). It's based on all Facebook sharing activity in September, as tracked by Newswhip.

It's probably no coincidence that the top three websites -- Huffington Post, Daily Mail, and Yahoo -- use "frictionless sharing" apps to automatically share some users' article-reading activity with their Facebook friends. While the apps push the boundaries of reader privacy, they also effectively spread stories.

Following them are some legacy media websites: BBC, The New York Times and The Guardian.

A few of the 40 most-shared news websites on Facebook.

Earlier: Huffington Post dominates Facebook’s most-shared politics stories last year | With ‘frictionless sharing,’ Facebook and news orgs push boundaries of online privacy