chmod of some pidfiles

Hello,

Today I found out some pidfiles of 'system daemons', have a 'weird' chmod.

[quis_at_istud ~]$ ls -l /var/run/cron.pid
-rw-------  1 root  wheel  4 Mar  1 19:25 /var/run/cron.pid

Can somebody tell me why it is 0600 ?
I don't think it will harm if it is 0644 ?

I think this is only useful if the security.bsd.see_other_uids sysctl is 
set to 0.

-- Jille