Now when you tap that Foursquare link, iOS 9 intelligently routes you to that exact place inside of the Foursquare app bypassing Safari altogether
Deep linking & search in iOS 9 will change everything
Nirav Savjani

And if you are in private browsing mode it will do that too! In fact if in private browsing mode, and a search result returns one of those links, then hey, why not deep link and remove all that privacy? Yeah, thanks Apple. Arg!