In a 1992 paper, van Douwen defined what he calls a

"gruff ultrafilter": an ultrafilter on the rational numbers which

is generated by perfect (this is, closed and crowded) sets; and

asked whether these ultrafilters exist, providing in the same

paper a proof that they do if cov(M)=c. The question of whether

the existence of gruff ultrafilters can be proved in ZFC alone

remains open, but further progress has been made in the

way of consistently positive answers. In this talk I will

present a proof that gruff ultrafilters exist in the Random

model, as well as in any model satisfying d=c. Joint work

with Michael Hrusak.