Code for a website logger?

[Logician]

There are tons of shareware programs around to track internet activity. The problems are:

a) Do you have Admin rights in the network (or local computer) to install these programs?

b) Does your deputy head abide by the same rules you do?

c) Is it ethical to track someone's site visits without his prior consent (especially considering the fact that he is your superior)

d) How can you prove he is the one who visited these sites even if you logged the internet activity in a local computer?