The log files are created by the syslogger. (syslogd) this program receives events, and sorts them into log files with help of /etc/syslog.conf After changing the syslog.conf, you need to reload the syslogger again. (...and not rebooting your entire machine for this

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Because log files can get very huge, a program called "logrotate" will be run periodically. It moves the files files to name.1, name.2, etc.. and eventually archives or deletes the logs. and yes, this program is ran from a cron job now and them. (which is a good thing)
but I have a question too; why do you want to change the permissions of the log files? they didn't kept them locked for normal users because it was a funny thing to do
