  Williams and Kramer [Phys. Rev. B {\bf 64}, 104506 (2001)] have recently
argued against the existence of staggered magnetic moments residing on several
lattice sites around Zn impurities in YBCO superconductors. This claim, which
is in line with an earlier publication by Williams, Tallon and Dupree [Phys.
Rev. B {\bf 61}, 4319 (2000)], is however in contradiction with a large body of
experimental data from different NMR groups. On the contrary, the authors argue
in favor of a very localized spin and charge density on Cu sites first
neighbors to Zn. We show that the conclusions of Williams and Kramer arise from
erroneous interpretations of NMR and NQR data.
