You have no idea how the person will react. Yes, for the person in the twitter thread it turned out to be helpful. For me the mental impact of that would probably be along the lines of someone breaking into my apartment. And I know that it would be absolutely horrifying to a lot of other people too.
You just can't know that you won't just inflict much more damage. So please, don't. Ask for consent. Explicit, informed consent. Beforehand. You need to respect people with mh issues. Thanks. 2/2