Or, even more drastical, see the difference in these lines:
perl -e '$_="bjzu-sbtz -abnzo-tbhze-rb zp-ebrzl- bhza-cbkze-r\n";s/[b-z]//g;print'
vs.
perl -e '$_="bjzu-sbtz -abnzo-tbhze-rb zp-ebrzl- bhza-cbkze-r\n";s/[b\-z]//g;print'
s$$([},&%#}/&/]+}%&{})*;#$&&s&&$^X.($'^"%]=\&(|?*{%
+.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e