eval "`locale`" is supposed to be safe. From
<http://www.opengroup.org/onlinepubs/000095399/utilities/locale.html>: "The
<value> and <implied value> shown above shall be properly quoted for possible
later reentry to the shell." glibc's locale command does not do this, and as a
result, if a script does eval "`locale`", it misbehaves badly when someone
figures out to set LANG to ' rm -rf /'.

$ LANG=' rm -rf /' locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG= rm -rf /
LC_CTYPE=" rm -rf /"
LC_NUMERIC=" rm -rf /"
LC_TIME=" rm -rf /"
LC_COLLATE=" rm -rf /"
LC_MONETARY=" rm -rf /"
LC_MESSAGES=" rm -rf /"
LC_PAPER=" rm -rf /"
LC_NAME=" rm -rf /"
LC_ADDRESS=" rm -rf /"
LC_TELEPHONE=" rm -rf /"
LC_MEASUREMENT=" rm -rf /"
LC_IDENTIFICATION=" rm -rf /"
LC_ALL=
$ echo $?
0