'Create Group' permission

Hi there,

For me, groups plays a very important role but I do not need for people to have the option to create/suggest a group. I have two profiles and have unchecked the button which allows them to create a group (which was very easy). My problem is that when an unregistered user logs to my site, they can see the 'Create Group' button which registered users cannot see.

My question is, how do I disallow the public to create a group?


Thanks in advance!