New Delhi, Jan. 21 -- Iranians have been struggling for nearly two weeks with the longest, most comprehensive internet shutdown in the history of the Islamic Republic - one that has not only restricted their access to information and the outside world, but is also throttling many businesses that rely on online advertising.

Authorities shut down internet access on Jan. 8 as nationwide protests led to a brutal crackdown that activists say has killed over 4,500 people, with more feared dead. Since then, there has been minimal access to the outside world, with connectivity in recent days restored only for some domestic websites. Google also began partially functioning as a search engine, with most search results inaccessible.

Officials have...