By default a form's saved data will not be accessible in the Form Data Browser. Access to form data is assigned to users by editing their iCM Privileges.
It is also possible to allow access to saved form data from the Forms Library while designing your form.
Right-click on a form and select "Secure this form's data". You'll be taken to a screen that lets you choose the iCM Groups/Users who are allowed access the form's saved data.
Use the "Select" button to add users. Highlight a user and click "Remove" to remove them.
If you press the select button you'll see a list of all of the users in iCM. Current users with access are highlighted. Double-clicking on users in this list is a quick way to add or remove their access to the form data. There's also a search control.
Take care when deciding which forms should be made available to the Form Data Browser. Any actions (email, workflow, and so on) that are present on a form will be triggered whenever that form is used to edit data within the Form Data Browser. See Form Data Overview for a full discussion.
A form will only save data to the the iCM database if a "Database Save Action" field is included in the form's design.
It is worth noting that securing a form's data in this way actually controls whether or not this form is available in the Form Data Browser to view data with. It is possible to view the data of another form if you design a form using an External Type Definition.