Deprecate User#__get(). It causes too many cache-related headaches

@@ -14,6 +14,14 @@ class User {
         $this->id = $this->ID = $this->_wpuser->id;
     }
 
+    /**
+     * @deprecated This method has caused MANY headaches with it's caching implementation.
+     *             It bypasses the metacache (which gets updated when any meta field is set
+     *             or retrieved), so causes the data used elsewhwere to be stale. BAD STUFF.
+     * @param $key
+     *
+     * @return mixed
+     */
     public function __get($key) {
         if (isset($this->_wpuser->{$key})) {
             return $this->_wpuser->{$key};