Failure to comply would make the search engines or speakers liable for, at least, statutory damages of $250/day plus attorney fees.
While that quote in the article is taken out of context it is even more disturbing when taken in context. The included video puts the quote in context where Comey is arguing against widespread access to strong encryption with the public. There are other quotes included as well that are just as disturbing such as:
Even our communications with our spouses, with our clergy members, with our attorneys are not absolutely private in America...
Is this the "adult conversation" on encryption he was getting ready for last year.
Marvelous! The super-user's going to boot me! What a finely tuned response to the situation!