Demontis et al. study transferability of adversarial examples and data poisening attacks in the light of the targeted models gradients. In particular, they experimentally validate the following hypotheses: First, susceptibility to these attacks depends on the size of the model’s gradients; the higher the gradient, the smaller is the perturbation needed to increase the loss. Second, the size of the gradient depends on regularization. And third, the cosine between the target model’s gradients and the surrogate model’s gradients (trained to compute transferable attacks) influences vulnerability. These insights hold for both evasion and poisening attacks and are motivated by a simple linear Taylor expansion of the target model’s loss.