  A planar polygonal billiard $\P$ is said to have the finite blocking property
if for every pair $(O,A)$ of points in $\P$ there exists a finite number of
``blocking'' points $B_1, ..., B_n$ such that every billiard trajectory from
$O$ to $A$ meets one of the $B_i$'s. As a counter-example to a theorem of
Hiemer and Snurnikov, we construct a family of rational billiards that lack the
finite blocking property.
