I'd need a module to global log chats; like the 'log' module, but loaded globally instead of users' side.
Thanks in advance.
I don't think there is a script for that already written - simply because of privacy reasons. I don't even know if ZNC is capable to do this.
Maybe the simplest thing to do is run znc in debug-mode in a screen and set a screenlog-file. In debug-mode, ZNC writes every incoming/outgoing line to stdout.
Another option is to load the log-module for every user.
take a look at the summary page at: http://sourceforge.net/projects/znc/