my %words;
my @blacklist_entries = qw(insurance Sxx porn buy viagra ZENIC 
                           Möbelkauf Bußgeld Führerschein);

my %rx_tab = map {$_ => qr:(^|\b)\Q$_\E(\b|$):} map {lc} @blacklist_entries;

while (my $line = lc <DATA>) {
  study $line;
  foreach my $k (keys %rx_tab) {
    $words{$k}++ while ($line =~ /$rx_tab{$k}/g);
  }
}

while (my ($key, $value) = each %words) {
  print "$key=$value\n";
}