This report and underlying data represent 417,972 unique URLs that were in 13,480,000 tweets that mentioned "ferguson" between August 10th and August 27th, 2014. You can learn more about how the data was collected here.
The URLs themselves were extracted from the collected Twitter data, unshortened (using unshrtn) and then loaded into redis in order to count them.
The urls.tsv.gz here is a tab separated file that includes the tweeted URL followed by the tweet URLs for any tweets that mentioned it.
The index.html file is a report of the top 100 URLs tweeted, which indicates whether the URL appears to have been archived by the Internet Archive. It uses the data found in urls.json, which is generated with urls.py.
Code and data are licensed with CC-BY