[Courses] Linux commands: /etc/crontab, crontab

[Christine Bussman]

My system is set up by default so that only root can set
up a cron job  (trying to execute crontab -l as another
user gives a permission denied error).  Is this a security
feature, and if so, what are the risks of disabling it? 
(i.e.
using chmod on /usr/bin/crontab)

Another 'quirk' on my system in comparison to what you
have described is that when I look at the contents of
/etc/crontab, it begins with
# remember to give cron a sighup when updating this file

Is this a function of what particular cron program I am
using?  (I installed vcron because that was what the
gentoo install guide suggested rather than the other listed
options)

Another system I use doesn't even have /etc/crontab,
and running the crontab command returns 'command not
found'.  I'm just curious how these systems relate to what
you are describing.

Christine