If I were a cop I'd be placing such ads on an open internet forum too.
Ha. You underestimate people.
I'm a moderator on Europe's biggest board on weightlifting and bodybuilding. We have people coming in and trying to buy and sell steroids all day everyday on an open board. Not cop people, real people. I need to spend more time kickbanning these idiots and deleting their offers/requests than actually moderating. It's absurd.
What should be legal/illegal or allowed/banned should be as straightforward as
perpetrator + victim = crime. What is absurd is the number of people on this planet that so eagerly jump on the state sponsored morality bandwagon and make crime an unbalanced equation. If two individuals willingly want to enter into any business transactions for a commodity that hurts no one but themselves, what business is it of ours, or the cops, or the state to interfere?