It seems to me that - as this is a User Experience site - every question posted could reasonably be tagged with user-interaction. It's more or less a meaningless tag. Certainly when I notice a question has been tagged with this it isn't tagged with anything of any relation to the actual post itself. It is often paired up with website-design too, but we can't really get rid of that one as not all UX questions are about web design, so it is still useful (albeit highly misused).
It seems that user-interaction is the default 'I don't know what to tag my question, so I'll just tag it 'interaction design' instead', which makes the whole purpose of tagging questions lose the purpose. I've been deleting uses of user-interaction when they appear to have been used in this way.
Should this tag be removed and blacklisted so that people have to actually tag their questions with something meaningful instead? We can just assume that every question posted is going to be related to User Interaction in general.
If you can think of a good reason to keep this tag around then leave an answer to show why, or leave your suggestions as to whether or not we should keep it around.