Mine

#!/usr/bin/perl
print "Converting all domain Default Accounts to :blackhole: ...";
opendir (DIR, "/etc/valiases/") or die;
while (my $file = readdir (DIR)) {
	if ($file =~ /^\./) {next}
	open (IN, "</etc/valiases/$file") or die;
	my @data = <IN>;
	close (IN);
	open (OUT, ">/etc/valiases/$file") or die;
	foreach my $line (@data) {
		if ($line =~ /^\*\:/) {
			print OUT "*: :blackhole:\n";
		} else {
			print OUT $line;
		}
	}
	close (OUT);
}
print "Done!\n";