The Bot Framework service must protect itself and its customers against abusive call patterns (e.g., denial of service attack), so that no single bot can adversely affect the performance of other bots. To achieve this kind of protection, we've added rate limits (also known as throttling) to our endpoints. By enforcing a rate limit, we can restrict the frequency with which a client or bot can make a specific call. For example: with rate limiting enabled, if a bot wanted to post a large number of activities, it would have to space them out over a time period. Please note that the purpose of rate-limiting is not to cap the total volume for a bot. It is designed to prevent abuse of the conversational infrastructure that does not follow human conversation patterns. For example, flooding two conversations with more content than two human could ever consume.