If you are only reading Knowino, the only information collected is what is normally collected in server logs. Knowino will not make specific information about its users available to any third party (including law enforcement agencies) unless required to do so by applicable law.
If you contribute to Knowino, your work is here to stay and will be associated with your account name (if you are signed in) or your IP address (if you are not signed in). You should be aware that IP addresses are traceable; the "traceability" of your IP address depends on your Internet service provider. If you are signed in with an account, only information that you volunteer about yourself and your identity will be made publicly available: we encourage you to introduce yourself on your "userpage", but it's best not to divulge highly personal or sensitive details.