The key authenticates its owner toward the BWHF hacker database server. It's like the CD key for Starcraft: you need a valid CD key which authenticates you toward Blizzard's battle.net servers.
Only those who possess a valid authorization key can report hackers to the central hacker database. Reports with invalid keys are discarded.
Only autoscan reports, manual scan does not report. However, if you have a key, you can send me your old hacker replays (only replays from 2009), and I can add them in your name (with your key).
Keys cannot be purchased. I give keys for free to those who can be trusted. This includes my friends and people I play with on battle.net. Of course this is a very limited group of people.
Moreover I provide keys upon requests to admins of known Starcraft websites and communities. Once I verified that the requestor is truly the admin he/she claims to be, I provide as many keys as needed. Then the admins are responsible to distribute the keys to people they know and whom they trust.
NEW! If you would like an authorization key, fill out the application form: Application form to get a BWHF Authorization Key
There is no guarantee whatsoever that you eventually will be granted one. Be as descriptive as you can. Give as many details as you can.
If I find that a key is used inappropriately, the key can be revocated at anytime without any warning. Revocation of a key means all reports that were done using that key will be excluded from all queries like they were never happened. Optionally those reports will be deleted forever.