An Apple Search engine on every iPhone, iPad and Mac could quickly damage Google’s core business. And Apple would probably be happy to do it.

A Facebook Search engine would add to the damage.

Bing-Yahoo and Yelp could ally with either of the above.

It could happen quite quickly and alienated advertisers would happily leave in droves to follow the traffic.

Read The Wall Street Journal article.

Later in the same comments section:

Apple already has a search engine. It is called Siri.