If you feel that it is just homework, then feel free to reply as such. Sometimes I have a similar feeling, though I tend to answer anyway. There are plenty of other cases, Like Navi, where I know that the examples he's generating are his own to deal with questions that he is asking himself. It's hard to strike a balance.
However, if a student comes here to get quick answers to save their skin the following morning, they might return to learn some more.
It's also hard to get them to guess answers to questions that they have asked. I haven't noticed anything recently that looked like someone dumping their entire homewrok task on the forum.
There are others who are clearly using the forum as a source of help for texts that they are reading for the media courses, which I feel is a legitimate use. Did you have any post in particular in mind?
On other fora, I have seen posts simply saying that they don't do homework. Feel free to follow suit and, if you have marked it as such, then I will refrain from answering. It's nice to have your input, both in answers and in ideas like this, so please do feel that where you think the forum is being misused, then let's try to sort it out.
Maybe we shouldn't answer for forty-eight hours so that they miss their deadline. )