monitoring staff workflow

Is there software we can install to monitor staff working, a have had a few that are currently using worktime to do alot of personal items such as browsing facebook, holidays and generally not working.

In my country (and I think in all EU) is almost always illegal to monitor the use that employees make of their PCs. In alternative one can monitor external logs (ip, url, bandwidth, etc) of a firewall and in case blocking them.

Why not block some of these things at the perimeter network? Firewall, content filter, dns filter, etc.
Might be time to have a word with employees if they are not following rules?