When I was a kid, thus a long time ago, whe were on a Sunday excursion to the Grand Ballon in the Alsace. There were toilets, as far I remember 4 or 5 in a row, with doors, only a small space on the bottom between the stalls. Well, what they did not mention is that when the person in the first stall flushed, it flushed all stalls. :-) as the flush could only be triggered in the first stall. As you can imagine, there was lots of screaming, as it was also a standing/hovering toilet.