You will need to edit the language string "pre_pinned" in "core_public_global" in the ACP.
ACP > Look & Feel > Manage Languages
You may need to unlock your language packs, to do this you need to do the following:
1. Navigate to your ACP
2. Hover over the Support Tab on your ACP nav bar
3. SQL Management > SQL Toolbox
4. Scroll to the bottom and put the following query in the "Run Query" Textbox
UPDATE core_sys_lang SET lang_protected = 0 WHERE lang_protected = 1
That should work for you.
Quote from Davlin from a topic similar to this:
The question(s) in this support topic have been answered and the owner has been able to solve the problem. Because of this, the support topic has been closed and moved. If you have other questions, please open a new topic.
I've never actually thought about this, I do indeed agree. It would stop users simply registering to promote their service and is not really "giving anything back to the community"