@SwampDonkey@DaLilFishie You wouldn't want to do this with most jellyfish species, but moon jellyfish stings have little to no effect on most humans. Still strange though, given how fragile jellyfish are.
@KevinB they monitor it pretty well. Only two groups are allowed at the touch tank at a time, and each group has staff watching them to ensure only the top of the jellyfish are touched, you can see how that would work based on the picture above. They also close it down for periods of time (I don't know how long) each hour or so to give them a rest.