def _check_security(self):
        predicate = getattr(self, 'allow_only', None)
        if predicate is None:
            return True
        try:
            predicate.check_authorization(pylons.request.environ)
        except WhatNotAuthorizedError, e:
            reason = unicode(e)
            if hasattr(self, '_failed_authorization'):
                # Should shortcircut the rest, but if not we will still
                # deny authorization
                self._failed_authorization(reason)
            if not_anonymous().is_met(request.environ):
                # The user is authenticated but not allowed.
                code = 403
                status = 'error'
            else:
                # The user has not been not authenticated.
                code = 401
                status = 'warning'
            pylons.response.status = code
            flash(reason, status=status)
            abort(code, comment=reason)
        except NotAuthorizedError, e:
            reason = getattr(e, 'msg', 'You are not Authorized to access this Resource')
            code   = getattr(e, 'code', 401)
            status = getattr(e, 'status', 'error')
            pylons.response.status = code
            flash(reason, status=status)
            abort(code, comment=reason)