Radio astronomy has begun to explore an exciting frontier, in which we can not only probe polarimetry in the time domain, but are doing so across enormous fields of view and with extremely broad instantaneous wavelength coverage. This has led to the discovery of new populations of magnetised objects that are extremely rare or that have very unusual properties. I will present some of the highlights from the new radio telescopes that offer these powerful capabilities, with particular focus on the wide-field polarisation capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) and on the enormous number of fast radio bursts detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME).