Via computer virus operating as morality police. "Arabic Trojan butts into porn surfing: Yusufali-A interrupts adult websites with messages from the Koran," from [1] ITNews, with thanks to Graeme:

Security experts today issued a warning after detecting a malicious Trojan horse which tries to interrupt the surfing of adult websites by displaying messages from the Koran.

The Yusufali-A Trojan monitors users' surfing habits by examining the title bar of the active window.

If the Trojan finds a key word such as 'teen', 'xx', 'sex' or 'penis', it minimises the window so that the user cannot see its content and displays a message from the Koran instead.

The message, which is partly written in Arabic, contains the following English text: "Yusufali: Know, therefore, that there is no god but Allah, and ask forgiveness for they fault, and for the men and women who believe: for Allah knows how ye move about and how ye dwell in your homes."

Graham Cluley, senior technology consultant at Sophos, said: "Unlike other malware, it appears that this Trojan isn't trying to steal money or confidential information, but acts as a moral guardian instead, blocking the viewing of websites it determines as unsavoury.