Your security concerns with an employee should not stop after that person is hired.
Every potential computer user should undergo fundamental education in security policy as a matter of course. At the least, this education should include procedures for password selection and use, physical access to computers and networks (who is authorized to connect equipment, and how), backup procedures, dial-in policies, and policies for divulging information over the telephone. Executives should not be excluded from these classes because of their status?they are as likely (or more likely) as other personnel to pick poor passwords and commit other errors. They, too, must demonstrate their commitment to security: security consciousness flows from the top down, not the other way.
Education should include written materials and a copy of the computer-use policy. The education should include discussion of appropriate and inappropriate use of the computers and networks, personal use of computing equipment (during and after hours), policies on ownership and use of electronic mail, and policies on import and export of software and data. Penalties for violations of these policies should also be detailed.
All users should sign a form acknowledging the receipt of this information, and their acceptance of its restrictions. These forms should be retained. Later, if any question arises as to whether the employee was given prior warning about what was allowed, there will be proof.
Periodically, users should be presented with refresher information about security and appropriate use of the computers. This retraining is an opportunity to explain good practice, remind users of current threats and their consequences, and provide a forum to air questions and concerns.
Your staff should also be given adequate opportunities for ongoing training. This training should include support to attend professional conferences and seminars, subscribe to professional and trade periodicals, and obtain reference books and other training materials. Your staff must also be given sufficient time to make use of the material, and positive incentives to master it.
Coupled with periodic education, you may wish to employ various methods of continuing awareness. These methods could include putting up posters or notices about good practice, having periodic messages of the day with tips and reminders, having an "Awareness Day" every few months, or having other events to keep security from fading into the background.
 If you do this, change them periodically. A poster or notice that has not changed in many months becomes invisible.
Of course, the nature of your organization, the level of threat and possible loss, and the size and nature of your user population should all be factored into your plans. The cost of awareness activities should also be considered and budgeted in advance.
The performance of your staff should be reviewed periodically. In particular, the staff should be given credit and rewarded for professional growth and good practice. At the same time, problems should be identified and addressed in a constructive manner. You must encourage staff members to increase their abilities and enhance their understanding.
You should also avoid creating situations in which staff members feel overworked, underappreciated, or ignored. Creating such a working environment can lead to carelessness and a lack of interest in protecting the interests of the organization. The staff could also leave for better opportunities. Or worse, the staff could become involved in acts of disruption as a matter of revenge. Overtime must be an exception and not the rule, and all employees?especially those in critical positions?must be given adequate holiday and vacation time. Overworked, chronically tired employees are more likely to make mistakes, overlook problems, and become emotionally fragile. They also tend to suffer stress in their personal lives?families and loved ones might like to see them occasionally. Overstressed, overworked employees are likely to become disgruntled, and that does not advance the cause of good security.
In general, users with privileges should be monitored for signs of excessive stress, personal problems, or other indications of difficulties. Identifying such problems and providing help, where possible, is at the very least humane. Such practice is also a way to preserve valuable resources: the users themselves, and the resources to which they have access.
A user under considerable financial or personal stress might spontaneously take some action that he would never consider in more normal situations?and that action might be damaging to your operations, to your personnel, and to the employee himself. When we read in the newspaper about someone who goes on a shooting spree in the office, who cleans out the corporate bank account, or who commits suicide, the coworkers almost always comment about how they knew he was stressed or acting funny. Too bad they didn't act to help head it off.
Managers should watch for employees who are obviously stressed; have trouble interacting with some other workers, customers, or vendors; have financial or health problems; have repeated problems with inappropriate use of computing resources (e.g., they are drawn to porn or gambling sites); or have other obvious troubles. Guiding them to counseling is a compassionate and humane thing to do, even if the behavior is severe enough to warrant termination. Most communities have low-cost or free services if other services are not covered under your company's benefits plan.
Ensure that auditing of access to equipment and data is enabled, and is monitored. Furthermore, ensure that anyone with such access knows that auditing is enabled. Many instances of computer abuse are spontaneous in nature. If a possible malefactor knows that the activity and access are logged, he might be discouraged in his actions.
Audit is not only done via the computer. Logs of people entering and leaving the building, electronic lock audit trails, and closed-circuit TV tapes all provide some accountability.
At the same time, we caution against routine, surreptitious monitoring. People do not like the idea that they might not be trusted and could be covertly watched. If they discover that they are, in fact, being watched, they may become very angry and may even take extreme action. In some venues, labor laws and employment contracts can result in the employer's facing large civil judgments.
Simply notifying employees they are being monitored is not sufficient if the monitoring is too comprehensive. Some studies have shown that employees actually misbehave more and are less productive when they are monitored too extensively. This is true whether you are monitoring how often they take coffee breaks, timing every phone call, or keeping a record of every web site visited.
The best policies are those that are formulated with the input of the employees themselves, and with personnel from your human resources department (if you have one).
Consider carefully the time-tested principles of least privilege and separation of duties. These should be employed wherever practical in your operations.
This principle states that you give each person the minimum access necessary to do her job. This restricted access is both logical (access to accounts, networks, programs) and physical (access to computers, backup tapes, and other peripherals). If every user has accounts on every system and has physical access to everything, then all users are roughly equivalent in their level of threat.
This principle states that you should carefully separate duties so that people involved in checking for inappropriate use are not also capable of contributing to such inappropriate use. Thus, having all the security functions and audit responsibilities reside with the same person is dangerous. This practice can lead to a case in which the person violates security policy and commit prohibited acts, yet no other person sees the audit trail or is alerted to the problem.
Beware of Key Employees
No one in an organization should be irreplaceable, because no human is immortal. If your organization depends on the ongoing performance of a key employee, then your organization is at risk.
Organizations cannot help but have key employees. To be secure, organizations should have written policies and plans established for unexpected illness or departure.
In one case that we are familiar with, a small company with 100 employees had spent more than 10 years developing its own custom-written accounting and order entry system. The system was written in a programming language that was not readily known, originally provided by a company that had possibly gone out of business. Two people understood the organization's system: the MIS director and her programmer. These two people were responsible for making changes to the account system's programs, preparing annual reports, repairing computer equipment when it broke, and even performing backups (which were stored, off-site, at the MIS director's home office).
What would happen if the MIS director and her programmer were killed one day in a car accident on their way to meet with a vendor? What would happen if the MIS director were offered a better job at twice the salary? What if the programmer, unable to advance in his position because of the need to keep a key employee in his role, became frustrated and angry at the organization?
That key personnel are irreplaceable is one of the real costs associated with computer systems?one that is rarely appreciated by an organization's senior management. The drawbacks of this case illustrate one more compelling reason to use off-the-shelf software, and to have established written policies and procedures so that a newly hired replacement can easily fill another's shoes.