I really like this initiative. I am Roennie, I work as a security consultant, with a very strong focus on system security (sysop perspective). Nowadays, I work on a freelance base, securing systems of customers.
I tend to focus on POSIX systems (Linux, *BSD, MacOSX), rather than Windows (Server). Over the years, I've -mainly private- disclosed vulnerabilities to manufacturers, developers, political parties, etc. I'm European, hoping to contribute knowledge here.