The second data release from the Gaia satellite has revolutionised our understanding of the Milky Way halo. One of the recent important discoveries made was a prominent population of stars in the inner stellar halo (within ∼ 10 kpc from the Sun) which have a high radial velocity anisotropy. This has substantial implications for dark matter direct detection experiments, but its unclear how much these stellar anisotropies reflect substructure in the dark matter halo. The community that is currently working on this is quite diverse, observational astronomers, N-body simulators and particle physicists. I will review the developments and points of dispute within this community as well as present my humble contribution, which came in the form of the paper arXiv:1910.07536.
