Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Will be reading this for the rest of my life.

Hardening Linux? Isn't Linux already secure? Well, yes, for ordinary use. But if you have valuable information on a Linux computer there are those who will try to get it, and might know how.This is the sort of book that covers the topics of interest to those who administer Linux systems that do have valuable information on them. The techniques described can keep the valuable information out of reach from all but the most determined and skilled cyber-crooks.