With the expansion of the SilverPhase I.T. infrastructure, support responsibilities have increased as well. To help keep your job manageable, you need to start defining limits for your users. One of these is the Acceptable Usage Policy. It defines what is and is not appropriate use of company I.T. resources. It usually ties in with your company's code of conduct and even has legal consequences.
The Fourth Amendment of the U.S. Constitution protects against unreasonable search and seizure and by default extends to computers used for business, even if the computers are owned by the company. So if, for example, you suspect that one of your users has inappropriate content on their work computer, you can't search their files without a warrant.
BUT......If your company has a documented code of conduct that includes appropriate I.T. usage policies AND your employees have read and acknowledged this policy, then the Fourth Amendment no longer applies to your employees in the workplace. That being said, if you find evidence of criminal activity (note that possessing pornography is not a crime), then you must immediately stop your investigation and notify law enforcement.
Write up a 1-2 page draft acceptable usage agreement for SilverPhase LLC that contains, at minimum, usage guidelines for:
Desktop PCs
File servers
Internet access