Tasks assigned to a resource will display in the resource's portal page, as well as the time and expense entry interfaces, even if the resource does not have read permission to the task. This allows the projects to be managed with detailed information while not allowing the resources to see the task detail. While this is a somewhat uncommon choice of configuration, one which often occurs as a result of a permissions administration mistake, it is designed to allow for this configuration.
The primary reason for a configuration in which assigned resources are not given read access to their own tasks is that the resources are contractors or customers contributing work and/or responsibility on a project within which they should not be allowed to see all of the work and scheduling information. A simple example might be a customer who has been assigned to a task in which completion represents review and approval of a change order. The customer can access the portal page and check off the task as completed without having access to the project task list view.
If a user without read access to the task clicks a hyperlink which would normally display the task detail view, or the project which would normally display the task list view, Project Insight will present a page with an "insufficient permissions" message.