Firefox: Nothing transmitted to Google until you perform a search.

Unity: Nothing transmitted to Amazon until you perform a search

Sure, I'm not agreeing with the default out of the box functionality, but other than the fact that user expectation is that a local search does not transmit information to remote servers (same issue as chrome's omnibox for typing URLs) it is exactly the same. But maybe Canonical should make it explicit what the default does (maybe they do, I don't know)

Install the OS, Click on gear icon (top right), settings, privacy, turn off online results

Point is your specific criticism can be levelled at firefox as well