Also, there are many PC key loggers, both soft and physical. They can save a special hidden, and/or encrypted file to the PCs HD, that you can read later. The physical ones store the strokes in flash memory, that you have to upload later. Most people don’t know about routers logging ip requests and routing, but this monitoring feature can be virtually disabled if a person uses a portal service that makes their browsing anonymous. What you will see is a set of address that are similar, or the same. If you were to trap the data, you would see a set of encrypted instructions as to what sites the person want to see, and a return of encrypted data back that contains the site. But this is expensive, and leaves a trail. Spy ware programs can also see some VNCs, VPNs, keylogers, etc… FYI. Some physical firewalls will also thart your efforts. Some physical firewalls will also thwart your efforts.
Some legal and ethical concerns (really just to bring up debate. I think you stated your purpose well. I don't doubt the need.):
In short, contact an HR specialist before you embark on this.
If you’re an employer, at least 2 states require that you let employees know that they are being actively surveyed at. Most other states allow companies to add it to the had book, and some allow the assumption that an employer will monitor their own resources with out haveing a policy.
Parents and guardians can monitor their kids, but you really don’t have any rites with the rest of your family, unless they are incompetent.
If the person you do this to is at any time a government employee while using the PC (lets say an , then you have just committed a felony (separate to violating any number of wiretapping and surveillance laws. Government employees are basically chattel for all intents and purposes, and some odd laws apply.) Also, if your state does not have specific laws concerning electronic surveillance, the person(s) you servile may sue and win damages. You are generally going to loose a jury trial, because nobody likes to be spied on, legal or not.
What this all comes down to, is even if your right, and prove some sort of crime, you may end up being wrong. So, for example, you prove that your spouse is cheating on you might end validating their arguments or end up in trouble because you use illegal means to get the evidence. There are gray areas, and ultimately, lawyers can argue anything.
If you are using this for an experiment, depending of the experiment, lack of full disclosure may prevent publication. While this may lead to a bias or adversely affect the experiment, lack of full disclosure can, for some human subject experiments, may put you in a world where you won’t get published. (I can’t see why this would be the case, but I also don’t know if your running an experiment.)
Any way, I won’t harp on the ethical issues. You are likely doing this for very good reasons and have thought about the morals and ethics that guide your behavior. I just mentiond them because I thought it might cause a debate.
What do you think is going on with the PC or the employee?