Piwik: On this web site with Piwik, an open source web analytics tool (http://de.piwik.org), collected and stored for marketing and optimization purposes. From these data user profiles can be created under a pseudonym. Cookies may be used. Cookies are small text files that are stored locally in the cache of web browser the visitor. Cookies allow us to recognize the visitor's browser. The data collected by Piwik without the explicit consent of the person concerned is not used to identify a visitor personally and is not aggregated with any personal data about the bearer of the pseudonym.