Ha. Never thought of that. But no, it's not a feature in the sense of something that was designed with this goal in mind. It's a way of not having to design and

Ha. Never thought of that. But no, it's not a feature in the sense of something that was designed with this goal in mind. It's a way of not having to design and implement a whole url scheme, and instead being able to easily run arbitrary code in response to a link being clicked. This architecture, however, has the undesirable (expect apparently to you) side-effect of occasional "unknown or expired link"s.