SharePoint 2010’s social tagging features let users in your organization categorize and find information easier. Aside from that nicety, Microsoft also notes social tagging can be used to show compliance with industry requirements or prepare for an audit or e-Discovery.  SharePoint 2010 uses these social tagging features:

·         The Note Board, for tracking comments in a central location

·         Ratings, for rating content

·         Bookmarklets, for adding tags and notes for pages outside of the SharePoint environment and displaying them on a user’s MySite

Users see social tagging information on their My Profile page, or by following a tag or a colleague, and by going to web pages on the SharePoint Server farm. IT manages social tagging features via Central Administration, a site collection, or a site. The tags are stored in a term store but neither the tagger’s identity nor the web page tagged are identified.  

There are definitely some privacy and security implications you should research before jumping into social tagging. To get started, see the Microsoft article “Privacy and security implications of social tagging (SharePoint Server 2010).”