Index: 0.10/httpauth/filter.py
===================================================================
--- 0.10/httpauth/filter.py	(revision 4892)
+++ 0.10/httpauth/filter.py	(working copy)
@@ -31,6 +31,8 @@
                 break
         if req.args.get('format') in self.formats:
             check = True
+        if req.args.get('user') in ['anonymous']:
+            check = False
         if check and not self._check_password(req):
             self.log.info('HTTPAuthFilter: No/bad authentication data given, returing 403')
             return self