Prepares the query variables.

Kills WordPress execution and displays JSON response with an error message.

Adds any sites from the given IDs to the cache that do not already exist in cache.

Kills WordPress execution and displays an error message.

Updates the cron option with the new cron array.

Processes arguments passed to wp_die() consistently for its handlers.

Adds metadata to a site.

Adds an additional class to the PHP nag if the current version is insecure.

Removes metadata matching criteria from a site.

Deletes everything from site meta matching meta key.