Fatwa is an Islamic religious law issued by a qualified mufti on various matters in accordance to Islamic law.
"It's not allowed for people to use what belongs to others without payment or without permission. Therefore, the Internet should be used only after subscribing for the service," said Dr. Ali Mashael, chief mufti at the IACAD.
Mashael added that the use of another person's Wi-Fi without the owner's consent is akin to "fraud, embezzlement and theft," according to Khaleej Times.
The prohibition also cited that the illegal use of Wi-Fi by others reduces Internet speed for the original user.
"Prophet Mohammed (Peace Be Upon Him) was reported as saying that: 'There should be neither harming nor reciprocating harm' and hence people should not be involved in such Wi-Fi theft," Islamic researcher Dr. Shaikh Mohammed Ashmawy said, as cited by Khaleej Times.
The new fatwa for Wi-Fi use was posted on the IACAD website on Monday.