FYI for anyone interested in using quantitative digital metrics to measure online collective action - as well as qualitative data for mechanisms - here are two articles that I just had published:
The Digital Activism Gap: How Class and Costs Shape Online Collective Action
https://academic.oup.com/socpro/article-abstract/65/1/51/4795348
Moral Monday is More than a Hashtag: The Strong Ties of Social Movement Emergence in the Digital Era
http://journals.sagepub.com/doi/full/10.1177/2056305117750719
Maison des Sciences de l'Homme et de la Société
Université Toulouse