In the latest release of Ubuntu, 12.10 there was a privacy leak discovered in the new Dash. When you search for an item, you will see Amazon advertisements of similar products as well from the internet (aka you make an internet search from your desktop and then by clicking on the links they will open in the browser). Now the search request is sent through https, which is secure, but the images from Amazon.com are sent back through insecure http. Thereby your IP, location and hence identity can be revealed.
EFF.org has a more detailed article on this and the latest show of Hak5 is also talking about the issue, hence I am just raising awareness here as well. If you have upgraded to 12.10 then you might want to solve this issue, what you can do quickly by reading on here or visiting either of the above two sites.
Disable Data LeaksTerminal
sudo apt-get remove unity-lens-shopping
From System Settings
Go to Privacy/Search Results and set "When Searching in the Dash" to "Off"