>Since most of such killers think that prostitution is evil per se and needs to be swiped off the face of the planet, I wonder where do they get the idea that the source of the trouble is on the supply side. Could it be something they learn from their environment?

Probably. I suspect many of the same people who use the service will vilify the prostitutes.

>Also, in any movie where I saw a brothel raid, they arrest the working class and the customers get as much as a slap on the wrist. Why do they get the preferential treatment? They were a party in the same trade.

It would make sense to either forbit both, or neither (working as a prostitute, and using her services).

>If prostitution is bad (which I agree with, though probably for different reasons than the most),...

I am curious about those reasons. Not because it is sinful, I am sure.

> ...wouldn't the simplest way to make it vanish be to cut the demand? With no market, this industry wouldn't exist. Is there any religion around here which tries to use this approach?

I am not sure about prostitution, but you probably know that many religions frown upon sexual intercourse, between people that are not married among themselves.

>And, on the same subject, in divorce cases, does purchase of sexual services constitute adultery?

I would personally consider this adultery - almost by definition. But I am not sure about the law.