One Install, Multiple Clients

I've done a pretty good job defining multiple projects in the same ActiveCollab instance, segregating projects by specific clients. But there are still a few places where a user assigned to "Client A" can note that other clients exist, say "Client B", including at login with the dashboard widget that shows "People who were online in the last 15 minutes:" ... heres my question ... is it possible to dig deeper into the config settings such that as Owner, I can add my 5 separate clients, manage their projects and not let them see each other without 5 separate installs?

So maybe I am only getting overly worried because client #1 and see on his/her dashboard that client #2 was online in the last 15 minutes; which is the case today, and I really didn't want them to necessarily know about each other. Perhaps I just have to remove that one widget from their dashboards, or modify the SQL command in the widget to only select where company=mycompany ...