for my $user ((sort { $users{$b}->{count} <=> $users{$a}->{count} } keys %users) {
   blah blah...
}

##</code><code>##

Global symbol "$user" requires explicit package name at

##</code><code>##

my @sorted_users = sort { $users{$b}->{count} <=>
    $users{$a}->{count} } keys %users;
for (@sorted_users) {
    blah... blahh
}