Far too many attacks come from inside an organization, perpetuated by disgruntled employees (or former employees who still have access remotely), by temporary contract workers who have a beef with the company (or do it “just for fun”), by IT staffers trying to make a point about the company’s security (or lack thereof), or even by people within the organization who have been paid off by a competing company or someone else who wants to sabotage the company’s IT infrastructure. There are many different motivations, but many organizations that spend big bucks protecting against outside threats still get victimized by trusted insiders.
Read here about some of the measures that you can take to prevent IT sabotage inside your company:
http://m.networkworld.com/news/2011/081911-how-to-prevent-it-sabotage-249919.html