You can either turn off the social media feature all together or you can hide it in following ways
1. Hide social tags using SocialRibbonControl sharepoint 2010 – A Microsoft SharePoint Server 2010 farm-level feature called SocialRibbonControl causes the I Like It and Tags & Notes controls to be displayed on the Documents and Items tabs of the ribbon for document libraries and lists, as well as on all browse pages. These controls enable users to tag and rate items and to leave notes on Web pages, including the users’ My Profile pages. By default, the SocialRibbonControl feature is enabled.
See the complete post about how to disable it @ Hide social tags using SocialRibbonControl sharepoint 2010
2. Using Social tagging permissions for users or groups – To Enable or disable social tagging permissions for users or groups see the complete post Disable\Hide social Tags, Notes for a group in Sharepoint 2010
3. Using Sharepoint:SPSecurityTrimmedControl – This allows the conditional display of content depending on the user’s permission. The content can be any HTML code or other controls. This will hide the links for some users according to the specified permission level.
Social media links on master page are generated by “<SharePoint:DelegateControl ControlId=”GlobalSiteLink3-mini” Scope=”Farm” runat=”server”/>” tag. So all you have to do is to add this tag in a security trimmed control and give the control appropriate permissions for trimming the tags. This will hide the tag for people with ManagePermissions on the site.
Something like below :
<Sharepoint:SPSecurityTrimmedControl runat=”server” Permissions=”ManagePermissions”>
<SharePoint:DelegateControl ControlId=”GlobalSiteLink3-mini” Scope=”Farm” runat=”server”/>
4. Using User Profile Service – You can also disable these links for some of the users by disabling the social media option for the group in the users profile service.
Steps would be :
1. Go to the user profiles and properties service application in central admin.
2. Click Manage User Permissions.
3. Uncheck Use social features for a user or group to make these buttons go away.