This special issue is the outcome of a thematic session that was held at Sociolinguistics Symposium 19 in Berlin, 2012 by Margreet Dorleijn and Anna Verschik. The aim of the thematic session was to explore the extent to which (descriptive) contact linguistics and language structure-oriented codeswitching studies can benefit from the immense amounts of data provided by the Internet. Since the advent of internet in our daily lives, a massive body of research on multilingual Computer Mediated Communication (henceforth cmc) has appeared. Focus of these studies is generally cmc-data as a phenomenon in its own right. Typical cmc-features like emoticons, typographical characteristics, the use and adaptation of different alphabets as well as pragmatic issues, style, etc. have received ample academic attention, not only from linguists, but from behavioural and social scientists as well (see e.g. Riordan and Kreuz, 2010a, 2010b; Pflug, 2011; Soffer, 2012). Sociolinguistic perspectives are also addressed in cmc studies, such as the creation of social identities on the web, the processes involved in the formation of virtual speech communities, gender studies, etc. (See for example the seminal work of Androutsopoulos, 2006.) The innovative language use, the specific cmc-driven features have been highlighted in numerous studies (some examples are Androutsopoulos, 2006; Nishimura, 2007; Danet and Herring, 2007; instead of, Jibril and Abdullah, 2013). The scope and perspective in this field of enquiry is predominantly on the cmc-data as such. However, where the majority of studies on (multilingual or monolingual) cmc-language have an interactional or discourse analytic approach (Danet en Herring, 2007; Vandergriff, 2006; Hinrichs, 2006) or are concerned with macro sociolinguistic issues such as language choice (see e.g. Androutsopoulos, 2007;