  The XENON100 collaboration has recently released new dark matter limits,
placing particular emphasis on their impact on searches known to be sensitive
to light-mass (below 10 GeV/c^2) Weakly Interacting Massive Particles (WIMPs),
such as DAMA and CoGeNT. We describe here several sources of uncertainty and
bias in their analysis that make their new claimed sensitivity presently
untenable. In particular, we point out additional work in this field and simple
kinematic arguments that indicate that liquid xenon (LXe) may be a relatively
insensitive detection medium for the recoil energies (few keV_r) expected from
such low mass WIMPs.
