To be able to exact big data from twitter, you have to register an API for twitter.
I installed Python3.5 and edit my Windows8.1 environmental variables setting from ‘advance computer system setting. I downloaded Tweepy (exacting data from twitter using python), and the tweepy could not be installed in my computer Command Prompt. It reminded me that I have to log in my computer as the administrator to be able to install tweepy. Of course, right?! Sometime you just lose the battle by doing something not very smart. I relogged in my computer as the administrator and problem solved.
Marco Bonzanini has written a full 7 blogs about how to do data mining from twitter if you ever interested in doing big data analysis.