As we all know, whenever you type a term or word in unity's dash search bar, the list of relevant and suggested entries will be displayed in the search results based on the word or term you entered. This is because the search terms are being sent to Canonical and other third party websites and those sites will suggest you some relevant applications or other stuffs. This is the biggest controversial feature and many users feel it very annoying and complain about privacy issues.
Of course, you can disabled this search feature manually yourself. To disable this feature, go to System Settings -> Security & privacy -> Search. Then, toggle from ON to OFF to disable this feature.
However, it isn't necessary in the upcoming Ubuntu versions. Yes, Unity's Online search feature will be disabled by default in the upcoming Ubuntu 16.04 LTS version, due for release in 21 April 2016.. This feature, however, isn't completely deprecated, but it will be disabled by default. When you type a word in Unity search bar, only the local files, folders and app results will be displayed. No search terms will be sent to Canonical or third party sites. If you want this feature, you can enable it too.
The Ubuntu desktop manager Will Cooke explains in his blog post,
First of all online search will be off by default. This means that out-of-the-box none of your search terms will leave your computer. You can toggle this back on through the Security & Privacy option in System Settings. Additionally, if you do toggle this back on then results from Amazon & Skimlinks will remain off by default. You can toggle them back on if you wish.
He also said that Unity dash online search feature will only be disabled in the fresh installation, not in the previous releases and upgrades. If you upgraded to Ubuntu 16.04 LTS from Ubuntu 15.10, the search will remain in Ubuntu 16.04 and you have to disable it manually if you want to.
The other notable features which are going to be abandoned in Ubuntu 16.04 LTS default installation are,
And also, the Music Store will be removed completely for 16.04 LTS onwards.
This clearly shows the Ubuntu development team respects the user's privacy. Indeed, It is a wise move. Ubuntu is improving all the time and it seems they are learning from the past mistakes.