Of course things would stop working at the most inconvenient hour of the day. In the information technology world, working with fragile pieces of software is a matter of daily routine. Of course programs stop working at the most inconvenient hour of the day - hardware failures are becoming rare. Of course we never break something while fixing a problem. The programmer is faced with the same problems.
Shadow passwords attempt to cure a real problem.
By the end of the eighties, computers had become fast enough that large-scale password cracking became practical. Like many UNIX password cracking programs, Alec's program takes encrypted passwords from a password file and tries to guess them in a systematical manner. It is amazing what it found when I first ran it on our own password files. Some people stated that such programs should not be made avail- able because they might help intruders to break into systems. The usual approach is to move the encrypted passwords to a so- called shadow password file that is accessible only to privileged programs.