Computers have become such a big part of everyday life everywhere - Computer security and threat prevention is essential for individuals and organizations. And organizations are taking computer security more seriously to protect their information systems at different levels starting from physical, Personal, procedural and/up to technical level. The measures at all these levels have made the business world more effective (but not completely) at blocking inside and outside threats. These measures have made it increasingly difficult for hackers or viruses to penetrate systems. The threat to the organization is more from insiders than outsiders, in this paper we will analyze what are the internal threats in organizations, why are we defenseless and allow threats to realize and the best practices to secure our organization�s data from inside threats