Manuel Egele, Leyla Bilge, Engin Kirda, Christopher Kruegel. CAPTCHA smuggling: hijacking web browsing sessions to create CAPTCHA farms. In Sung Y. Shin, Sascha Ossowski, Michael Schumacher, Mathew J. Palakal, Chih-Cheng Hung, editors, Proceedings of the 2010 ACM Symposium on Applied Computing (SAC), Sierre, Switzerland, March 22-26, 2010. pages 1865-1870, ACM, 2010. [doi]