The number of articles downloaded from Sci-Hub is shown over time. Sci-Hub access logs were combined from two releases: (Elbakyan and Bohannon, 2016) covering 27,819,963 downloads from September 2015 to February 2016 and (Tzovaras, 2018) covering 150,875,862 downloads from 2017. The plot shows the average number of downloads per day for months with data. There were 54 days within the collection periods without any logged access events, due presumably to service outages or server misconfiguration. Hence, we ignored days without logs when computing monthly averages. Point color indicates the proportion of days with logs for a given month. For example, November 2015 and October 2017, which were missing logs for 17 and 23 days respectively, are thus lighter. The December 2017 dropoff in downloads likely reflects the effect of domain suspensions that occurred in late November (Silver, 2017). Unlike the Sci-Hub log analyses elsewhere in this study, this plot does not filter for valid articles (i.e. DOIs in our Crossref-derived catalog of scholarly literature).