It really is an interesting thing, though.
Rather than needing a specific rule against a specific thing, a space I'm a member of (member-driven space) has the general community norm that all areas have a volunteer steward of sorts, and that person is expected to manage that chunk of space ... so they'd have to be explicitly told of anything new that would be left, either as a project or a space-shared tool. That kinda covers it ... if someone is willing to deal with it and take responsibility for it, it can happen. If not, not.
I'd very much like to have someone set up a mining rig .. if they were willing to talk about it and let others learn from the experience.
In the winter, at least, the heat generated would nearly balance out any electricity cost in our climate.