Abstract: It has long been conjectured that global symmetries can only be approximate in a theory of quantum gravity. In this talk, I discuss two pieces of work to quantify this statement, putting lower bounds on the amount of violation. In the first calculation, I discuss the global symmetry violation in a black hole evaporation process. The degree to which symmetry is violated can be quantified by computing a suitably designed quantum information quantity of the Hawking radiation. In the second calculation, I discuss a more direct way of quantifying global symmetry violation using scattering amplitudes. I will discuss an explicit wormhole solution that contributes to such amplitudes. The talk will be based on arXiv:2011.06005 with Henry Lin and an upcoming paper with Ibrahima Bah and Juan Maldacena.