There has just been a study published in Science (Harvey et al., 2015) that is interesting because it forces the dark matter hypothesis to contradict itself.
Harvey et al. have looked at the light from familiar objects like galaxies as seen from behind galaxy clusters, and looked at the distortion in the images due to gravitational lensing. They know what a typical galaxy looks like: a disc, so if it looks like a U-bend instead when it's behind the galaxy cluster, then they can infer the bending of the light that must be occurring and assume this bending is due to dark (invisible) matter in the cluster. They looked at 72 galaxy cluster collisions, and have modeled the collisions using several kinds of dark matter, and have shown that the only kind of dark matter that fits the observations, is a kind that doesn't interact with itself. I'd like to point out here that this makes the dark matter hypothesis self-contradictory since it is well known it must repel itself to stay spread out in the halo of galaxies, and yet this study now shows it must not interact with itself. So dark matter dissappears in a puff of logic? Well, I'm sure someone will think of a way to make it more complex to save the hypothesis, but it gets ever more ridiculous.
In contrast MiHsC says that there is no dark matter (see my blog here and my paper here) and that the light is bending because its inertial mass varies due to the variation in acceleration within the cluster. I know the inertial mass of light is a controversial issue, but it has never been well understood, and MiHsC predicts galaxy rotation, cosmic acceleration, the flyby anomalies, the emdrive (light in a box) and many other anomalies quite well without invisible entities or contradictions.
Harvey D, Massey R, Kitching T, Taylor A, Tittley E. The non-gravitational interactions of dark matter in colliding galaxy clusters. Science 27 March 2015. Read more at Phys Org
McCulloch, M.E., 2012 Testing quantised inertia on galactic scales. Astrophysics & Space Sci., 342, 575-578. Preprint. Journal.