All models are now using ActiveModel::ForbiddenAttributesProtection, which shifts the responsibility for parameter whitelisting for mass-assignments from the model to the controller. attr_accessible has been disabled and removed as this functionality replaces that.
The require_parameters method in the ApplicationController has been removed in favor of strong_parameters' #require method.
It is important to note that there is still some refactoring required to get all parameters to pass through #require and #permit so that we can guarantee that parameter values are scalar. Currently strong_parameters, in most cases, is only being utilized to require parameters and to whitelist the few places that do mass-assignments.
The email parameter is now required using strong parameters and will throw ActionController::ParameterMissing if it is missing. If the email address is incorrect or invalid, Discourse::InvalidParameters will still be thrown.
Robin Ward
Sam
Ian Christian Myers
Brian Plexico
Régis Hanol
Gosha Arinich
Jakub Arnold