Social media such as wikis, blogs, and social networks are increasingly being used internally within companies. Businesses expect "Enterprise 2.0" to lead to more effective communication, improved knowledge management, and increased attractiveness to young applicants. However, the question of how working conditions and requirements change from the employees' perspective and what challenges arise for corporate co-determination has so far been neglected. Based on case studies from companies, the book presents findings on the experiences, requirements, and approaches of employees and interest representatives regarding social media.