When I first discovered that there was a taint option to use warnings, I was pretty jazzed at the ability to lexically turn on and off data tainting. Not that I knew why such a thing would be useful, but it just seemed cool. So I tried it:

#! /usr/bin/perl
use strict;
use warnings FATAL => qw(taint);

my $tainted = shift;

open (OUCH, "> $tainted");
close (OUCH);
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Nay. The filename passed on the command name was used; the file was created. I tried both with and without the FATAL => part, as I'd found in perldoc perllexwarn.

Then it occurred to me that perhaps no warnings qw(taint); might work to block the -T switch. Nay again.

So now I wonder what the heck taint is doing in the use warnings tree at all.