I would need to read the paper to be sure, but from what I gathered a simpler SEO explanation hasn&#x27;t been given.<p>With the Snowden leaks each and every media outlet started publishing reports on those topic. That means that the Google SERPs of relevant keywords started to be clogged by relevant articles and editorial contents that displaced Wikipedia entries from the first positions. I&#x27;ve done my share of editorial SEO stuff during the last few years and I&#x27;ve seen that happen many times for even smaller events.<p>A more meaningful way of testing this would have been to have a similar sampling of entries from another topic to test against the key group. Maybe that&#x27;s in the paper, we&#x27;ll see when it&#x27;s out. Still, the numbers are consistent with the fluctuation of positioning in Google results.