monitoring other sites

our parent company sent out a letter saying that they will be monitoring all network related activity. that is all well an good because i know users are not using the internet for company business but for personal use as well.

my questions are:
is there a way that they can monitor my site without having an administrator log on to my site?
my site is total different than theirs, the two sites are connected through a cisco PIX501 router so that the parent company can access 2 application programs. there are 3 people do not have any admin rights just domain users rights. is there a way for them to monitor our network through the cisco router?

Thanks,