As you may know, Canonical has developed the Unity Smart Scopes project for Ubuntu 13.10 Saucy Salamander, transforming the Dash into a search area, acting itself like a search engine, capable of searching on both the local computer and online websites. Read this article to find out more about the Unity Smart Scopes (100 Scopes).
From privacy issues, many users prefered not to use the scopes, but the Ubuntu developers have decided to anonymize the images before serving them to the Dash, in order to please the users.
So, the online services are not able to gather information about the users using the Smart Scopes at all. The words typed in the Dash reach the Canonical servers, who decides the best results and anonymized them before they are sent to the user’s Dash.