In this post we will see how we can delete recently opened files from Ubuntu's Unity dashboard. Why would I do that you ask? Answer is privacy but then again it largely depends on the usecase. There should not be such a need for a strictly persona computer but if it is shared it is better to delete history when you leave.
How to delete recently opened files history in ubuntu 14.04
Open security and privacy settings from unity dashbaord.
Then go to Files & Applications and select clear usage data and select the period you want to clear data from -
Click Ok and you are done.