What makes it funny exactly? To use an analogy (a poor one, like all), if this were a medical advice board, and someone had said 'I've got aids and i'm looking

What makes it funny exactly? To use an analogy (a poor one, like all), if this were a medical advice board, and someone had said 'I've got aids and i'm looking for a good retroviral" and the reply was "Chemo! <ducking>"..... I don't find that funny at all... just smug cancer weenies.