Online communities like Flickr, del.icio.us and YouTube have established themselves as very popular and powerful services for publishing and searching contents, but also for ident...
Tom Crecelius, Mouna Kacimi, Sebastian Michel, Tho...
Online social networks (OSNs) are popular collaboration and communication tools for millions of users and their friends. Unfortunately, in the wrong hands, they are also effective...
Hongyu Gao, Jun Hu, Christo Wilson, Zhichun Li, Ya...
It is a widely held belief among designers of social tagging systems that tag clouds represent a useful tool for navigation. This is evident in, for example, the increasing number ...
Denis Helic, Christoph Trattner, Markus Strohmaier...
CAPTCHAs protect online resources and services from automated access. From an attacker’s point of view, they are typically perceived as an annoyance that prevents the mass creat...
Manuel Egele, Leyla Bilge, Engin Kirda, Christophe...
—Established in 2005, YouTube has become the most successful Internet site providing a new generation of short video sharing service. Today, YouTube alone comprises approximately...