purpose of /var/backups

[Doug Poland]

Hello,

On my 5.3-STABLE systems I have a directory in /var called backups.  A
view of man hier says: 

   backups/   miscellaneous backup files

with files like:

  aliases.bak
  aliases.bak2
  group.bak
  group.bak2
  master.passwd.bak
  master.passwd.bak2

I'm curious, what process are writing these files to this directory?
Does something depend on these files existing?

-- 
Regards,
Doug