He's probably talking about the data leaks that are associated with Dash and the Amazon ads; basically, whatever you search for with it is sent over to whomever, Amazon in this case, but not necessarily only them.
For reference:
https://prism-break.org/en/categories/gnu-linux/#operating-systems - see the last comment, which is about Ubuntu
https://www.eff.org/deeplinks/2012/10/privacy-ubuntu-1210-amazon-ads-and-data-leaks
So, if you're not already using it, you might want to switch to the Debian based Mint and avoid the Ubuntu one.
For reference:
https://prism-break.org/en/categories/gnu-linux/#operating-systems - see the last comment, which is about Ubuntu
https://www.eff.org/deeplinks/2012/10/privacy-ubuntu-1210-amazon-ads-and-data-leaks
Quote
Unless you have opted out, we will also send your keystrokes as a search term to productsearch.ubuntu.com and selected third parties so that we may complement your search results with online search results from such third parties including: Facebook, Twitter, BBC and Amazon. Canonical and these selected third parties will collect your search terms and use them to provide you with search results while using Ubuntu.
So, if you're not already using it, you might want to switch to the Debian based Mint and avoid the Ubuntu one.
Well its very easy to disable those searches:
http://askubuntu.com/questions/192269/how-can-i-remove-amazon-search-results-from-the-dash-or-disable-the-feature
The problem is, that is the only reported placed in which the data leaks happen; but no one knows if that is the only place where they happen. By using Ubuntu, or any other distro that is based on it, you basically have to trust them that no more information about you is being collected and sent elsewhere.
The prism-break page has a link to the discussion page in which they go into more detail about it: https://github.com/nylira/prism-break/issues/334
