In SharePoint 2010, you can remove the “I like it” and “Tags and Notes” buttons in various ways, as suggested in the blog post Hide Like it, Tags and Notes in Sharepoint 2010:

• disable it from the entire SharePoint farm via the farm feature “Social Tags and Note Board Ribbon Controls”, as described in the article Activate or deactivate the SocialRibbonControl farm-level feature (SharePoint Server 2010);
• disable social tagging permissions to users and groups, as described in the blog post Hide I Like It and Notes and Tags;
• hide the social buttons via css (as described in How to Remove I like it — Tags and Notes using SharePoint Designer) or via SPSecurityTrimmedControl;
• use the User Profile Service.