It was showing people that posted on your timeline, and showed up on your timeline, it doesn’t scan their timelines for information.
The information is not exactly public, but the property of Twitter. Their Developer Terms of Service (when using the API) is fairly strict - for example, you can get away with duplicate posts via the web interface and usually spamming out to multiple trending hashtags or mentioning (@user) users. However, that behavior can lead to an account being banned (we have had it happen) when using the API. Twitter realizes there is a difference between “human eyes” and a “robot” and treats them differently.
We do our best to go by the Twitter Terms of Service. Some folks have modified the Core to behave differently, and that is fine, the bot is open source. However, if their accounts are blocked or post-banned, we cannot provide support at that time. We already had a long talk with Twitter some time ago when we provided a generic account for folks to use that was banned and they gave us a laundry list of “do’s and do not’s” which we take pretty seriously after having an account banned. We apply what they told us to the way that the bot behaves to protect users from having that happen to them. I understand it is a bummer, but, that is why we do it.