This chapter explores user protest against algorithmic personalization on social media through the analytical lens of communicative materiality and focusses on the algorithm-user relationship, accounting thus for the complex entanglement of algorithmic structure and user behavior. Empirically, the chapter draws on an analysis of user comments. User protest against algorithmic personalization often emerges irregularly and spontaneously, and is self-motivated and highly emotional. Users seem to make a strong connection with their information feed, and they are hence deeply affected when alterations are made. Algorithmic personalization has turned abstract information feeds into personal and intimate information spaces, which prompt forms of ‘connective action’ when modified without consent. Especially feelings of powerlessness and loss of control trigger such responses. Further research therefore should look deeper into how algorithms affect people’s feelings and how such reactions translate into practices of technological resistance.