diff -r bd8afb90ebf2 Lib/json/__init__.py
--- a/Lib/json/__init__.py	Sat Sep 29 09:44:17 2012 +0200
+++ b/Lib/json/__init__.py	Sun Sep 15 09:24:57 2013 +0530
@@ -302,6 +302,10 @@
 
     The ``encoding`` argument is ignored and deprecated.
 
+    Encoding will NOT be automatically detected and issues have been found 
+    with Unicode BOM (Byte Order Mark) signature. Use utf-8-sig while decoding 
+    json strings from files with utf-8 BOM signature.
+    
     """
     if (cls is None and object_hook is None and
             parse_int is None and parse_float is None and