Funny things. Squats.
On the plus side, you can knock holes in the walls and no one really seems to mind, on the other hand they do tend to be little beacons for absolute-batshit-crazy.

Kesselburg as a case in point. They had really nicely kitted wood and metal workshops, and a couple people there were super proactive and productive, making all kinds of stuff and trying their best to improve the place. Whereas the other two thirds were still, after years, living under tarpaulins in the woods and the only work being done on the existing buildings (it's an old Stassi training facility) was in making them worse.
This I found really surprising. I'm used to communities in New Zealand, where the first thing you do is build some kind of amazing house for yourself.

It seems a common thread in these types of places, and the problem seems to be openness. Basically, if you are somewhere that anyone and everyone can stay, you end up with all the people who have nowhere else to go. And of course junkies and the profoundly mentally ill need as much as anyone somewhere to live, but you don't necessarily want to be the poor bastard who has to deal with them.

It was the same at the Open University squat in Berlin. It was set up a while ago as a free space for learning and art, and for the first couple years it was, but then the government started shutting down support for the mentally ill, and a lot of them ended up there because it was nearby and no one had the heart to physically throw them out. As more came in the originals got fed up and left, now the place is basically uninhabitable.

Kesselburg wasn't anywhere near so far gone, in fact it was mostly pretty sweet, but there was definitely a fair bit of crazy going on.
I had a good time, nonetheless.

And now I'm in another squat, in Malaga. La Casa del los Monos.
But this isn't an open squat. You can't just walk in and find yourself a corner to sleep in, it's more like a normal flat. I'm here because two of the originals passed through Kesselburg and invited me.
So the place is a lot less crazy, and generally more proactive.

Funny things communities; that the only way to make a space where people want to live is to prevent most of them from living there.