Civil liberties and rights such as freedom of expression, press, thought, religion, association, lifestyle, and equality against the law are being subjected to fierce controversies within the socio-political landscape of Western developed countries. Based on a literature review, we develop two working hypotheses aimed at explaining divergent attitudes toward civil liberties among politically charged online communities on each side of the political spectrum. First, a “libertarian attitude” among rightist groups, in which economic conservatism suppresses the illiberal tendencies of social conservatism and right-wing authoritarianism. Second, a “illiberal attitude” among leftist groups, elicited by the rise of authoritarian forms of social justice-seeking within some influential left-wing ideologies. We report a correlational study using a cross-sectional sample (n = 902), whose results support both hypotheses. Lastly, we discuss these results in relation to polarization over civil liberties and perceived power imbalances between conservatives and liberals.