[Zope] How to disable anonymous sessions

[Gaute Amundsen]

I thought this must be in the FAQ or something, but 20 min googling does not 
turn up much usefull.

Closest I got was this: http://svn.nuxeo.org/trac/pub/ticket/600

At the moment we have 657 objects in /temp_folder/session_data
and this must be quite a bit of overhead.
We also have over a thousand "INFO(0) ZODB conflict error" a day, that I 
suspect are related to this.

This should be simple, but I can not spot it :-(

Anyone?

Gaute Amundsen