It shouldn't hurt anything if you have usb drives attached and you experience large power spikes or drops it could hurt them but this is the same for your computer.
The Pi itself has no moving parts it has a fail safe if voltage gets to high it will turn off just unplug and wait it can take time depending on how bad the hit was and for how long but should be fine.
The worst that will typically happen is you get a power drop and the sd card becomes corrupt eject and put image back on card.
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