Given the question What happens when all passengers jump at once?, I wonder what would happen if they all moved from side to side. If all the passengers moved from the front to the tail, or the other way around, there might be balance problems, but what if they moved from right to left (or vice versa)? I imagine the fuselage is not wide enough for this to seriously affect the aircraft's balance, but I would like confirmation for this assumption.
To have the greatest visible effect, the answer may focus on aircraft with relatively wide fuselages (for instance, A380, B747, B777). Maybe the effect is more visible for aircraft with smaller wingspans, thus, answers may also mention GA aircraft with a large enough body-width-to-wingspan ratio (the opposite of a glider).