Legal qualification of denial-of-service attacks

Denial of Service (DoS) attacks are not a phenomenon of recent years. Nevertheless, they have gained actuality in connection with the protests against the founder of the whistle-blower platform WikiLeaks, Julian Assange. As recent attacks against the websites of SPÖ and FPÖ demonstrate, DoS attacks are becoming an instrument of political expression. This raises the question as to the qualification of such attacks in criminal and civil law.