The ones that are just beginning, like first year or high schoolers, and say so in the beginning could probably need some help. The demanding ones, or the ones that are looking for final year projects (but never have any specific function in mind) can go to hell.
While I was in school, I had so many ideas, just no time or money. Come to think of it, things haven't changed that much... I don't understand how a college kid would make it so far into an engineering degree, have such huge resources at his finger tips, need to get complete strangers to do the assignments. Doesn't seem like the course work is any tougher. If they aren't interested enough to even try, why bother getting the degree in the first place?