By Tom's logic, any victim of any crime is the cause of that crime by not stopping it. There's always something one can do to better protect oneself from criminal activity. "You could have prevented it by not doing x" is a stupid way to look at causality in this instance. The cause of a crime is the person who commits the crime.
Leaving your phone on a crowded restaurant bar isn't anything at all like having private photos stolen from a computer. Still, the person who leaves her phone on a table isn't the cause of the theft of her phone. The cause of the theft of her phone is the person who took something that doesn't belong to her. The fact that thieves invariably exist doesn't legitimate theft at all.
Frankly I think it's troubling that some believe that vulnerability actually legitimates immoral, unethical, or otherwise forceful behavior, rather than making it more despicable.
It's been said several times in this thread that y'all aren't saying that the thief did nothing wrong, just that the victim also bears responsibility for the theft by creating the stolen goods. That's like blaming a painter for creating a work valuable enough to be stolen from her. It makes no sense. Obviously creating a valuable painting is not behavior that minimizes the risk of stolen paintings. In the same way, creating a nude photo is not behavior that minimizes the risk of stolen nude photos. That's just a truism. And it doesn't have anything to do with fault or blame or causation.