In response to rising unemployment and European governments’ concomitant austerity politics, and inspired by the protests of the “Arab spring”, a wave of popular protests have swept through Europe. The popular mobilizations have been particularly large in Southern Europe, but related protests – e.g., “occupy” protests – have also occurred in other parts of Europe. These protests can be regarded as a new generation of anti-capitalist protest, and while socialist groups and labour unions have been involved, the mobilizations also appear to have attracted adherents among new groups within the population. Correspondingly, the collective action frames have not fitted unambiguously with the traditional leftist interpretative repertoire. In this paper we will enquire into the specificities of this contemporary protest wave through a comparison of the participants in these protests with participants in protests more clearly anchored in the traditional left, such as annual May Day demonstrations. We focus on the socio-demographic composition of the protests as well as the participants’ motives for taking part. In addition, we compare how the continuities and discontinuities between “old” and “new” anti-capitalists vary with national context. The study is based on the protest survey dataset constructed within the research programme CCC: caught in the act of protest, contextualizing contention, and we compare protests in Belgium, Italy, the Netherlands, Spain, Sweden and the UK, taking into consideration the countries’ different “varieties of capitalism” as well as the political and economic opportunities of the traditional labour movement.