Wowpedia:NDA policy

Wowpedia has a strong commitment to remain within the appropriate legal boundaries for an official Blizzard Warcraft fansite. This means that contributors of Wowpedia are not allowed to add information or pictures to the encyclopedia which Blizzard would like to keep private. Particularly, when a game is in alpha production a non-disclosure agreement (abbreviated to NDA) is enforced that all participating which obliges all participating users to abide by strict rules.

From the official website:
 * You agree that you shall not, under any circumstances, [...] create, reproduce, distribute, display or otherwise make available screen shots or videos depicting the Program or any element thereof without the prior written consent of Blizzard
 * The existence of the Alpha Test and all elements thereof (including without limitation this Agreement) is confidential, and you agree to maintain secrecy associated with the Alpha Test until such time that Blizzard releases such information publicly. For purposes of example and not limitation, you agree that you will not disclose the following:
 * General comments about the systems utilized in the Program, including, but not limited to, the races, classes, combat, magic, communication, grouping, questing, and monetary systems.
 * Any general comments regarding the storyline behind the Program, including, but not limited to the story itself, non-player characters, quests, player races, classes, and items, armor, and weapons, of both a magical and non-magical nature.

Blizzard has enforced its NDAs. When World of Warcraft: The Burning Crusade was in alpha testing and a few pictures of elekks were uploaded, the wiki administrators received an email from the Entertainment Software Association which included a cease-and-desist order.

Action may be taken against accounts which persist in posting information covered by an NDA. Please bear in mind that datamined content obtained by individuals who have not agreed to the NDA is also covered by this policy and will be treated the same way.