Maybe I'm misunderstanding the problem but does this do what you want? 
use strict;
use warnings;

while(<DATA>) {
    print unless /(evil|bad|wrong)/i;
}

__DATA__
This string contains no blacklisted tokens.
This string is evil and wrong.

[download]

Updated: added i switch.

In reply to Re: Blacklisting with a Regular Expression by AReed
in thread Blacklisting with a Regular Expression by BenjiSmith

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