Facebook is updating its platform policy guidelines to prohibit developers from making it easy for users to accidentally send app notifications to hundreds or thousands of friends with one click.

While Facebook has taken product steps to solve this problem with the multi-friend selector for invitations and notifications, it is now adopting more general policy positions for all viral channels with which it can enforce punitive actions against overly-spammy applications.

The updated guidelines are listed in the Developer Wiki, and go into effect at 12pm PT on Tuesday, June 17. They are summarized by these overarching principles:

• Users must not be surprised by the outcome of an action they take.
• To ensure users only take actions they intend, an application must avoid one-click triggers of actions that apply to multiple people, except in special circumstances.
• To ensure users only take actions they intend, multiple recipients must be selected by the user, rather than pre-selected by the application.

As social networks continue to update their policies to take into account the different ways developers are using (and abusing) different communication channels, platforms are taking different policy approaches to viral channel access. MySpace recently prohibited applications from offering any game-like incentives for sending app messages. By contrast, Facebook is allowing users to send as many messages as they like, as long as the recipients are actively chosen by the sender.