@@ -146,7 +146,6 @@ class ACL(object):

         if self.hasGrant(name, permission):

             return

-        name = name.lower()

         permission = permission.upper()

         if "ALL" == permission:

@@ -159,12 +158,17 @@ class ACL(object):

         grantee.name = name

         grantee.permission = permission

-        if  name.find('@') <= -1: # ultra lame attempt to differenciate emails id from canonical ids

-            grantee.xsi_type = "CanonicalUser"

-            grantee.tag = "ID"

-        else:

+        if  name.find('@') > -1:

+            grantee.name = grantee.name.lower

             grantee.xsi_type = "AmazonCustomerByEmail"

             grantee.tag = "EmailAddress"

+        elif name.find('http://acs.amazonaws.com/groups/') > -1:

+            grantee.xsi_type = "Group"

+            grantee.tag = "URI"

+        else:

+            grantee.name = grantee.name.lower

+            grantee.xsi_type = "CanonicalUser"

+            grantee.tag = "ID"

         self.appendGrantee(grantee)