Apple doesn't have spiders crawling the Net or a big index of results already built up.
As far as know, since the Microsoft/Yahoo search deal, Yahoo doesn't have those things either. Microsoft handles that for them. Yahoo Search is now just a front end for Bing.
I suppose Apple could come up with a similar deal with Microsoft for iSearch. It's Yahoo's variety of other properties and brands that have the value now.
When packed with explosives, this sounds like a perfect tool for assassination. Make it cheap, decrease noise, increase range, add some further refinement in stealthily bringing it into a location (composite materials?)....
German software company SAP appears to be a possible target.
Real programs don't eat cache.