After you perform this procedure, users will not see the I Like It or Tags & Notes controls when they browse pages or edit document libraries and lists.
To activate or deactivate the SocialRibbonControl feature by using Central Administration
1. Verify that you have the following administrative credentials:
* You must be a member of the Farm Administrators group, or you must have been assigned permission to administer the User Profile service application that is running in the farm. For more information, see Assign administration of a User Profile service application (SharePoint Server 2010).
2. On the Central Administration Web site, in the System Settings section, click Manage farm features.
3. In the list of features, in the Social Tags and Note Board Ribbon Controls row, do one of the following:
* Click Activate.
* ClickDeactivate, and then click Deactivate this feature.
http://www.learningsharepoint.com/2010/07/07/hide-like-it-tags-and-notes-in-sharepoint-2010/
