Hiding Dashboards from Users

I know it's easy to hide custom dashboards from users but what about the default dashboards that come with vCOps and other Adapters?  As it is, when a new user logs in they default to about 30 dashboards open.  We really only want them to see the dashboards that are shared to them and not all the default dashboards without having to close all the dashboards when first logging in.

Is there a way to restrict access to the default dashboards?

Thanks

Mark