If you can feel the pulsation in the brake pedal, then it is most likely rotors. It could be rotors even if you don't feel it in the pedal because opposed-piston calipers don't send much signal back to the pedal.

If you mostly feel it through the car, check for loose ball joints and control arm bushings. Any little irregularity in the rotor can set up a nasty pulse cycle if there is loosness anywhere in the system. I have some hard spots in my rear rotors that showed up when I had the rotors turned. At at a certain brake temperature and speed, the whole rear end of my car shakes annoyingly.

I would not expect that there is any danger involved, just annoyance.