The competing interactions in highly frustrated magnets often
lead to very interesting emergent phases that are not possible in
conventional antiferromagnets. An example of such a phase is the classical
“Coulomb spin liquid” which for example, occurs in spin ice compounds that
have and continue to generate much interest in the magnetism community as
an experimental realization of emergent “magnetic monopoles”. A crucial
signature of the Coulomb phase is the unusual *pinch-point* shape of the
spin structure factor in momentum space which is experimentally accessible
through neutron scattering. I will discuss a theory for the full spin
structure factor across a range of settings which establishes the fate of
the pinch points at low and high temperature, for Ising and Heisenberg
spins, for short- and long-ranged (dipolar) interactions, as well as in the
presence of disorder. I will also discuss how putting non-magnetic disorder
in spin ice induces a very interesting spin glass phase where the freezing
and the topological spin ice phase are inseparably entangled: spins missing
due to the dilution become effective degrees of freedom that undergo
freezing at low temperatures, with the fluctuating background spin liquid
contributing towards the interaction of the hole-spins.