At the intersection of digital identities and new language and social practice online is the concept of searchable talk (ST). ST describes the process of tagging discourse in a social networking service (SNS) with a hashtag (#), allowing it to be searchable by others. Although originating in Twitter, ST has expanded into other SNS, and is used therein not only to mark language-based posts, but also multimodal posts and images. While scholars have elucidated the structure and function of ST, their studies have primarily examined ST within language-based posts; few have researched ST with respect to images and other types of multimodal environments. In addition, ST has primarily been explored in its SNS of origin, Twitter. This project directly addresses these gaps by adopting a social semiotic approach to ST in three SNS with very different technological affordances, Twitter, Tumblr, and Pinterest. Through a multimodal discourse analysis (Kress, 2009) combining both linguistic and other visual methods, I ask how visual and linguistic choices operate semiotically across SNS environments with different affordances and constraints. Specifically, I uncover the multiple meanings of Beyonce across a data set of 300 tweets, posts, and pins composed from entering "#Beyonce" in the search engine of each SNS. I argue that 13 meaning-based identity categories emerge for Beyonce, and link these meanings to their visual and linguistic expressions. I then compare these findings across modes and across platforms. Ultimately, I assert that this cross-platform approach elucidates Beyonce as a cultural object subject to reinterpretation where #Beyonce means much more than just "Beyonce." That is, when considering its multiple roles and meanings, #Beyonce becomes a site of visual and linguistic "indexicality" in a process of entextualization. In this process, it is SNS users' reinterpretations -- linguistically and visually -- that realize racist, sexist, and hegemonic Discourses, as well as those of emancipation and resistance. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]