Another criticism leveled against Foucault's approach is that he often studies the discourse of "prisons" rather than their concrete practice; this is taken up by Fred Alford: "Foucault has mistaken the idea of prison, as reflected in the discourse of criminologists, for its practice. More precisely put, Foucault presents the utopian ideals of eighteenth-century prison reformers, most of which were never realized, as though they were the actual reforms of the eighteenth and nineteenth centuries. One can see this even in the pictures in "Discipline and Punish", many of which are drawings for ideal prisons that were never built. One photograph is of the panopticon prison buildings at Stateville, but it is evidently an old photograph, one in which no inmates are evident. Nor are the blankets and cardboard that now enclose the cells."