Not unless someone punches them from the top :lol:
All the weight is evenly distributed on the three figures in each row, and the bubbles are protected by the card above them, actually it's the figures that are the heaviest part of each MOC and not even they weigh a lot.
Damage can occur from stacked star cases because the cases can "imprint" the card under the stress but it's gotta be a pretty big stack to do so. I also heard once that someone
with a stack of acrylic cases had a bunch of the ones at the bottom shatter but again -that's more the weight of acrylic not the actual MOC, crisp packets weigh more than Vintage MOC :lol: