Subscribed to issue when mentioning it in another issue
The other day I copied the URI for a gitlab issue (like this one) and pasted it into a comment of an issue in another organization's separate (& non-public, not that it should matter) gitlab.com-hosted issue tracker ...and then I was subscribed to the issue I copied & pasted, without even being asked. This is unintuitive, reminds me of Facebook-style auto-signup nonsense, and is a potential privacy problem (was my user in the public list of 'participants'? Unfortunately I didn't check before manually unsubscribing [toggling 'Notifications']).
Additionally, now, even after unsubscribing (from an issue I never explicitly subscribed to), if I am logged in while viewing that issue, I forever see a line in the comments/history saying my user mentioned the issue in another gitlab.com-hosted repo. As long as that is there I will always be confused as to why two separate repos and separate issue trackers that I have always purposefully kept separate are hopelessly & inexplicably intertwined, and what the privacy implications of that are. I can appreciate that it is a hosted solution and to a certain extent it is all one thing that is not actually separate, but there obviously also needs to be a certain amount of privacy & separation for this system to work, and I think part of that should be that what I've just described does not happen.
(Also for now I will be obfuscating copied & pasted gitlab issue tracker addresses so I don't have to experience this again. I doubt that is the intended outcome.)