diff --git a/README.rst b/README.rst
index 35c1f301..513376c7 100644
--- a/README.rst
+++ b/README.rst
@@ -69,6 +69,7 @@ History
     - Added get_creator for user, group and organisms
     - Added omitEmptyOrganisms to get_users
     - Added support for group admins
+    - Added support for bulk group creation/deletion
     - Repaired GFF3/Fasta downloading
 - 3.0.4
     - `Fixed bug <https://github.com/galaxy-genome-annotation/python-apollo/issues/4>`__ in deleteFeatures (Thanks `@NeillGibson <https://github.com/NeillGibson>`__)
diff --git a/apollo/groups/__init__.py b/apollo/groups/__init__.py
index e09a5ade..336f80a4 100644
--- a/apollo/groups/__init__.py
+++ b/apollo/groups/__init__.py
@@ -15,11 +15,14 @@ def create_group(self, name):
         Create a new group
 
         :type name: str
-        :param name: Group name
+        :param name: Group name (or a list of groups to create)
 
         :rtype: dict
         :return: Group information dictionary
         """
+        if isinstance(name, list):
+            name = ','.join(name)
+
         data = {'name': name}
         return self.post('createGroup', data)
 
@@ -28,11 +31,14 @@ def delete_group(self, group):
         Delete a group
 
         :type group: str
-        :param group: Group name
+        :param group: Group name (or a list of groups to delete)
 
         :rtype: dict
         :return: an empty dictionary
         """
+        if isinstance(group, list):
+            group = ','.join(group)
+
         data = {
             'name': group,
         }
@@ -146,7 +152,7 @@ def update_organism_permissions(self, group, organism_name,
         response['permissions'] = json.loads(response['permissions'])
         return response
 
-    def update_membership(self, group_id, users=[]):
+    def update_membership(self, group_id=None, users=[], memberships=[]):
         """
         Update the group's membership
 
@@ -156,13 +162,25 @@ def update_membership(self, group_id, users=[]):
         :type users: list of str
         :param users: List of emails
 
+        :type memberships: list
+        :param memberships: Bulk memberships to update of the form: [ {groupId: <groupId>,users: ["user1", "user2", "user3"]}, {groupId:<another-groupId>, users: ["user2", "user8"]} (users and groupId will be ignored)
+
         :rtype: dict
         :return: dictionary of group information
         """
-        data = {
-            'groupId': group_id,
-            'users': users,
-        }
+
+        if not group_id and not memberships:
+            raise Exception("group_id+users or memberships is required")
+        elif len(memberships) > 0:
+            data = {
+                'memberships': memberships
+            }
+        else:
+            data = {
+                'groupId': group_id,
+                'users': users,
+            }
+
         return _fix_group(self.post('updateMembership', data))
 
     def update_group_admin(self, group_id, users=[]):
diff --git a/apollo/users/__init__.py b/apollo/users/__init__.py
index cf635b6e..438d5201 100644
--- a/apollo/users/__init__.py
+++ b/apollo/users/__init__.py
@@ -2,6 +2,7 @@
 Contains possible interactions with the Apollo Users Module
 """
 import json
+import time
 
 from apollo.client import Client
 from apollo.decorators import raise_error_decorator
@@ -41,12 +42,14 @@ class UsersClient(Client):
     def _handle_empty(self, user, response):
         """Apollo likes to return empty user arrays, even when you REALLY
         want a user response back... like creating a user."""
-        if len(response.keys()) == 0:
+        found_response = len(response.keys()) > 0
+        retries = 0
+        while not found_response and retries < 10:
             response = self.show_user(user)
-
-            # And sometimes show_user can return nothing. Ask again...
-            if len(response) == 0:
-                response = self.show_user(user)
+            found_response = len(response) >= 0 and response != []
+            if not found_response and retries > 1:
+                time.sleep(1)
+            retries += 1
         return response
 
     def get_users(self, omit_empty_organisms=False):
diff --git a/arrow/config.py b/arrow/config.py
index 05f326f1..0b8245cf 100644
--- a/arrow/config.py
+++ b/arrow/config.py
@@ -23,4 +23,4 @@ def read_global_config():
         return DEFAULT_CONFIG
 
     with open(config_path) as f:
-        return yaml.load(f, Loader=yaml.safe_load)
+        return yaml.safe_load(f)