Guidelines for Adding Subjects to a Stream

According to the SSF specification, a receiver can add any subject to a stream. This means that the receiver can obtain events for any end-user, as long as the events are listed in events_delivered. Doesn’t this raise security and privacy concerns?

If there were a rule such as “only events related to the subject associated with the access token used when creating the stream will flow into that stream,” then things would be more straightforward, and there would be no risk of infringing on the security or privacy of other users. However, the SSF specification deliberately defines an Add Subject endpoint, allowing receivers to add arbitrary subjects to a stream.

It seems that, unless significant restrictions are imposed on the operation of transmitters and receivers, security and privacy issues will arise. Are there any operational or implementation guidelines to address this?

Start by reviewing the SSF specification's Add Subject endpoint and the meaning of events_delivered, then trace how receiver access tokens and subjects are described. Done means the repository contains agreed operational or implementation guidelines that address the stated security and privacy concerns.