It’s not a metaphor. But it is a warning. Here’s the intriguing bit:

A few weeks ago, I discovered that Google knows the lifespan of a goat. Search for “how long does a goat live” and you’ll see it displayed in a special card above the search results. 15 to 18 years! It’s not an important fact, and I can’t imagine people ask it very often — but there it is. I couldn’t tell you where they got the answer (it’s surprisingly hard to nail down, as I’ll get into later) but I’m pretty sure it’s right. It’s the kind of accidental discovery that Google loves to serve up. I went looking for a fact, and there it was. You come away feeling as if the engine knows the answer to any question you could ask.

The official name for this feature is the Knowledge Graph, Google’s project for converting information on the web into easily managed cards. The sudden appearance of the goat data says a lot about the piecemeal way Google has been building it. How long had they known about goats? I made a few calls and Google got back with an answer: the card was added a year ago, as part of a broader animal expansion that also included a goat’s mass (45 to 300 kilograms) and height (40 to 58cm), with similar specs for other beasts. Unless you’d thought to Google “how long does a goat live”, you would never have known.

Why Google is learning about goats – Russell Brandom, The Verge (28 October 2014)

Read the full piece for the warning bit. Spoiler: what we think of is fact can be just a lot of good guesses.