In your admincp, go to the "unregisterd users/users not logged in" user group (admincp -->usergroups-->Usergroup Manager) Go to edit the specific user group, scroll down till you find "Forum Viewing Permissions" and set "Can Download Attachments" to no..
I think that might be what you're trying to do?
Hi,
Thanks for the reply. What you have suggested is actually for the attachment. Is there a way that I can restrict this to pictures posted using img code?