anti-Muslim rhetoric [@tellmama] by right-wing populist movements [@Greven2016] and right-leaning media outlets [@the-independant-Sun], often conflating refugees and Muslims with Islamic fanatics [@diene2006muslims]. This rhetoric has also gained adoption online [@UNHCR-UNGP], prompting governmental agencies[^2] and NGOs to call on social media platforms to step up their efforts to address the problem of hate speech [@the-independant-hate-crimes; @tellmama]. The concern is that the increase in hateful narratives online led to an upsurge in hate crimes targeting Muslim communities [@the-independant-hate-crimes]. Insights into how online expressions of hate thrive and spread can help stakeholders’ efforts to de-escalate existing tensions [@burnap2014hate].

![image](framework-4.pdf){width="82.00000%"}

In this paper, we explore [*how hate speech targeting specific groups on social media is affected by external events*]{}. Anchoring our analysis in a series of Islamophobic and Islamist terrorism attacks in Western countries, we study their impact on the prevalence and type of hate and counter-hate speech targeting Muslims and Islam on two different social media platforms: Twitter and Reddit.

[**Our contribution.** ]{} We conduct a quantitative exploration of the causal impact of specific types of external, non-platform specific events on social media phenomena. For this, we create a lexicon of hate speech terms, as well as a collection of 150M+ hate speech 