At the visitation day for the school I am planning on attending, we got to sit down privately with the current cohorts of grad students in the program for some real questions about life in the program. Basically, it comes down to a "don't ask, don't tell" sort of mentality at least where I am at. Everyone knows that NYC is friggin expensive, and that the funding levels, while at the top end of the spectrum nationally, are still really not that feasible to live on. As long as your academic work and requirements for your fellowship/stipend are not suffering because of one or two quiet shifts of work, there is generally no problem. But if one has to give...work has to go.