>>1137272The only way I know of that an image could be justified as being illegal, immoral, or, evil is if you where to argue that by looking at said evil image you would likely then have evil thoughts and thus be more likely to act-out those evil thoughts making you a bigger "potential" threat.
The major flaw with this argument however is that it effectively justifies thought-crimes and doesn't take into account, at least fully, that humans have free will and thus freedom of choice.