Social networks, photo communities and chat apps are extremely popular among young people. The focus is always on self-expression and communication via the Internet. However, there are also downsides, such as data protection problems, (cyber)bullying and sexualized self-portrayal. The teaching material "Mobile media - new challenges: Selfies, Sexting, Self-Expression" offers an overview of the most popular services, provides information on risks and problems, and includes three projects for direct use in the classroom. The material is also available in an English version.