Can I watch (Big Brother) people?

[Gregory Gulik]

A user on my machine posed a question to me that I couldn't
answer:

Is it possible to watch what people are doing?  Not just (ps), but
what is being sent to their screens?

I tried doing 'tail -f /dev/tty??' on a tty that was doing something
but it doesn't work.

Is there a way of doing this?  I heard IBM mainframes can do this.

Can UNIX do it?  SHOULD unix do it?

-greg

-- 
Gregory A. Gulik
	...!jolnet!gagme!greg  ||  gagme!greg at jolnet.orpk.il.us
    ||  gulik at depaul.edu