tree f8c9c03e6dcbabd6cf4747fcd674c0fdc03bedd1
parent fc514ca3578c59753e059fd6b8a2415424850535
author John Wright <wrightlabs@gmail.com> 1326755359 -0800
committer John Wright <wrightlabs@gmail.com> 1326755359 -0800

It appears the Security class has been added to the system/core folder and is loaded automatically as well. 
Using $this->load->library('security'); in controllers currently returns FALSE, yet you might not notice because the Security class is already loaded.
I discovered this because of a custom Loader class I was using returned an error when loading the Security class.