While the internet may feel like a public park, when you access twitter's API you are connecting to their servers, which are not owned by the state. They are owned by a private entity.
Private entities can make whatever rules they want for their property as long as those rules don't break laws.
Twitter says don't reverse engineer. You reverse engineer. They block you. They can do that. If you actually break a law and cause damages with your reverse engineering, they can consider suing you. They can do that too.
If you are ignorant to the terms in which someone is offering a service to you then you are only exposing yourself to unneeded risk.
> Private entities can make whatever rules they want for their property as long as those rules don't break laws.
Yes. At the same time, people can use whatever publicly accessible resource in any way they like, as long as they do not break any laws.
The crucial point here is that the object of this discussion is a publicly accessible API. That, by design, comes with some elementary rights which cannot possibly be revoked by the fact that the API's provider puts something into their ToS. One of such rights is the right to use these APIs.
When someone uses these publicly accessible APIs and based on their experience then makes logical reasoning and conclusions about how they work, it might be considered as reverse engineering. But I cannot imagine how could a thought process be legally forbidden by any ToS in any way.
When someone then publishes their findings about the functionality of this public API, they are merely publishing the results of their reasoning based on facts that are publicly available. It is in essence a research result based on publicly accessible input data. Again, I cannot imagine how could such an activity be legally forbidden by the existence of some ToS.
> terms in which someone is offering a service to you
This service is offered as a publicly accessible API in the first place. The fact that someone might enter into a contractual relationship with the API's provider and therefore have their rights restricted is irrelevant for the purpose of this discussion.
Its main topic is the usage of this publicly accessible API without any contractual agreement.
If someone claims that a mere usage of some publicly accessible resource immediately constitutes entering into some contractual agreement, such provisions need to be supported by the law. And I am unaware of any legal obligations to agree with the publicly accessible API provider's ToS before using the API.
The API provider can put almost whatever they want into their ToS. The important part is whether or not it is backed by the law.
Private entities can make whatever rules they want for their property as long as those rules don't break laws.
Twitter says don't reverse engineer. You reverse engineer. They block you. They can do that. If you actually break a law and cause damages with your reverse engineering, they can consider suing you. They can do that too.
If you are ignorant to the terms in which someone is offering a service to you then you are only exposing yourself to unneeded risk.