CAPTCHA smuggling: Hijacking web browsing sessions to create CAPTCHA farms

@inproceedings{Egele2010CAPTCHA_smuggling,
  title     = {{CAPTCHA smuggling: Hijacking web browsing sessions to create CAPTCHA farms}},
  author    = {Egele, Manuel and Bilge, Leyla and Kirda, Engin and Kruegel, Christopher},
  booktitle = {Proceedings of 25th International Symposium on Applied Computing},
  month     = {March},
  year      = {2010},
  address   = {Sierre, Switzerland},
  isbn      = {978-1-60558-639-7}
}