From the legal stuff that came with 14.04.2:
"When you enter a search term into the dash Ubuntu will search your Ubuntu computer and will record the search terms locally.
. . .
Unless you have opted out . . . we will also send your keystrokes as a search term to productsearch.ubuntu.com and selected third parties . . . including: Facebook, Twitter, BBC and Amazon.
. . .
By searching in the dash you consent to:
the collection and use of your search terms and IP address in this way; and
the storage of your search terms and IP address by Canonical and such selected third parties (if applicable)
. . .
Online Search
You may restrict your dash so that we don’t send searches to third parties and you don’t receive online search results. To do this go to the Privacy panel and toggle the ‘Include online search results’ option to off. . . . "
- - - - -
But it doesn't say that Ubuntu doesn't keep the data anyway.
Good grief, there must be a lot of money in the data collection business.