I think your have two questions: 1.monitor their activity on their PC or laptop without their knowledge. 2.access confidential company dat and treat it without care.
To solve your problems, there are tools you can use. But perhaps the first thing to do is let people know that your IT folks will be monitoring their usage of company computers, etc. Here's an article that might give you a good place to start: http://www.anykeylogger.com/how-to-monitor-employee.html which tells you how to monitor employees' desk and alert when special files or folders accessed, copied and so on.
