My OS is Ubuntu 12.04.1 Desktop version (32bit). I want to create a new group called restricted which allows its users to use Audio devices and Video devices only, and I want to add a user called visitors to that group. By using Users and Groups, I was able to create a new user account called visitors, and a new group called restricted. But I can't figure out how to add those settings to the group restricted, and add the visitors user account to that group. I tried Google-ing, but every search result was about accessing root privileges and all, and I couldn't find answers on this specific topic.