Indeed, I'd guess Google especially is interested in whether the user is a sheep, given ads are their primary revenue stream. But "the goog's" evaluation of /that/ (and the algorithm by which they determine it) is almost certainly proprietary and not subject to open sourcing. Additionally, the result is probably more complex than could be properly expressed by a boolean, altho given specific enough border parameters it should be reducible to a boolean.
Which of course is where gathering all that data about a person comes in (for google and other, including government), the better to set the border parameters at which the boolean result is "true". =:^\