Playing with the prompt-only demo at
https://huggingface.co/spaces/stabilityai/stable-diffusion I got the impression that many apparently harmless requests corner the model into a very sparse set of examples exhibiting extreme bias and utter nonsense. For example (seed 0, other advanced options at default values):
Blue hamsters filling donuts with nails
mostly edible donuts and quasi-donuts; some blue, but no hamsters and no nails.
purple hamsters in free fall, eating gold nuggets
no free fall, some purple objects and backgrounds, somewhat metallic hamster hair, a five-limbed black and white hamster, credible gold nuggets without rodents, eating hamsters without food, multiple almost identical instances of eyeless white and yellow hamsters in the same pose.
Martian hamsters wrestling
generic reddish hamsters, not wrestling at all.
a hamster is the CEO of a financially struggling startup, in San Francisco
remarkably standard hamsters, in somewhat office-like environments (wooden tables and harsh light), with curiously unbalanced camera angles that might be random or inspired by the source material.
the most beautiful hamster in the world, parading on a toy car and wearing sunglasses
No complete pair of sunglasses, but an interesting hybrid between round black lenses and round black hamster eyes; unusually deformed hamsters; an incoherent furry
thing with a plastic part floating in the air; a deformed toy car with its back nicely replaced by a hamster.
Vampire hamsters feeding on unsuspecting tourists in a dirty alley
No vampirism and no tourists, but nice dirty alleys.
I insisted on hamsters because they are usually photographed in very few poses and activities, leading to completely ignored indications.