Unity is the default desktop environment used in world's most popular GNU/Linux distribution, ie Ubuntu. Unity's online search feature has got serious criticism due to it's privacy policies. Unity 8, the latest version of Unity, will be fixing privacy issues related to online search feature.
According to a news article published in softpedia linux section:
The search in Unity has been the source of serious debates in the past few years, but that should change dramatically with the new Unity 8, which no longer needs the current privacy tab that is available in the options.We all remember the storm of disapproval that swept over the Linux community when Canonical announced that queries in Unity would also search online sources. The developers implemented an option in the security entry, the Settings panel, to help users disable that kind of online search. Now, Ubuntu devs are hard at work on Unity 8, the current desktop environment on Ubuntu Touch, and they have made some serious modifications.