#!/usr/bin/perl -w
use strict;
my @avoid= map qr/\Q$_\E/i, qw(leroy brown);
my $log= "/home/psmith/logfile";
open( IN, "< $log" )  or  die "Can't read $log: $!\n";
my $line;
while( $line= <IN> ) {
    print $line   unless  grep $line =~ $_, @avoid;
}