In this article, I discuss the process of designing an object to protest against a specific surveillance device: the IMSI catcher, a controversial object used to monitor GSM networks. Being widely used in protests, I develop a tactical approach based on obfuscation to be adopted collectively to counteract IMSI catchers. In this case study, (1) I present how can remaking an IMSI catcher allow to re-appropriate the technology and create a basis for designing a disobedient object; (2) I introduce some examples of tactics to defeat surveillance based on obfuscation and the potential of inflatables; (3) I conceptualize a possible design of an object to defeat IMSI catchers and show the types of interactions it might generate in protests.