Team member Home page - how to restrict access

 Hi,

From team member home page, user is able to see the tasks for which the person is task manager or a team member.

However, when user clicks on the project hyperlink, user gets to see all the tasks of the project and also can update the progress of any of the task.

I feel that should not happen; user should be allowed to update progress of only those tasks for which user is responsible.

Can anyone help in letting me know - if any setup is required to do so?....or that's how it works.