def clean_timestamp(self):
        ts = self.cleaned_data["timestamp"]
        if time.time() - ts > (2 * 60 * 60):
            raise forms.ValidationError("Timestamp check failed")
        return ts
Make sure the timestamp isn't too far (> 2 hours) in the past.
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/contrib/comments/forms.py/CommentSecurityForm.clean_timestamp