Social plugins let you see what your friends have liked, commented on or shared on sites across the web. All social plugins are extensions of Facebook and are specifically designed so none of your data is shared with the sites on which they appear.
A. Traud, P. Mucha, and M. Porter. (2011)cite arxiv:1102.2166
Comment: 82 pages (including many pages of tables), 8 multi-part figures,
"Facebook100" data used in this paper is publicly available at
http://people.maths.ox.ac.uk/~porterm/data/facebook100.zip.