>"Nonetheless, online brute force would still be manageable. If each page view produces an average of 50 candidates, and one in every thousand page views is a login (this might be slightly optimistic), that's 50,000 attempts necessary in order to find a working login. HN gets about 500,000 hits on a busy day, so this could be done in a day or two while likely staying under the radar."
You would have a fnid that is in the cookie hash table, yet you still would not know to which username it is mapped to, correct?