I’ve heard about that. In a sense it’s sort of both since it can really mess someone up if they aren’t aware of the magnet. Someone told me awhile ago they can now do more than shut off the pacemaker and can even adjust the settings with specific magnets to reduce the need for invasive procedures. Not sure what the extent of that is but pretty neat if true!

Currently strong magnets can still mess with pacemakers. Fun fact, some modern phones have magnets in them that can do that - be careful about resting your phone on your chest if you have a pacemaker. I think the wireless charging unit is to blame.