an initial list of terms (keywords and hashtags) used in social media campaigns related to anti-Muslim hate and counter-hate speech. This list was assembled retrospectively (as was the rest of our data) using

news articles and blog posts discussing social media usage during hate and counter-hate campaigns,[^4]

resources from NGOs or governmental agencies tracking or analyzing hate speech on social media [@awan2015we; @UNHCR-UNGP], and

research articles [@magdy2016isisisnotislam].

Selected terms were individually validated by manually searching for them on both Twitter and Reddit. Additional co-occurring terms found in this process were added to the list. This step resulted in a list of $91$ terms, including “‘\#f\*\*\*quran,’’ “\#nosharia,” “ban islam,” and “kill all muslims.”

[**Query Expansion.** ]{} We then employed a query expansion heuristic to identify further terms that may appear in messages expressing hate or counter-hate towards different groups, including, but not limited to, Arabs and Muslims. The heuristic considers terms frequently appearing in social media messages matched by the terms in our initial list. To obtain a high-recall collection, we considered any new term that may constitute hate or counter-hate speech, using an inclusive, broad definition inspired by @silva2016analyzing and @chatzakou2017mean, and expanded to also cover commentary and counter-hate speech 