Don't ever cut your cat's whiskers, and certainly don't even think about plucking them! Not only are these acts extremely cruel due to your cat's need for their whiskers, but due to the intricate neurological network, plucking your cat's whiskers can be extremely painful.
If a cat's whiskers are cut, they feel disoriented and frightened, and will often hide and cower. This could be compared to blindfolding a human, due to the loss of a vital sensory input.
Whiskers don't need grooming or trimming in any way. They will naturally shed and grow back, just like fur. This means that if you ever find a whisker around the place, don't worry! Your cat is likely just shedding their old whiskers and growing new ones.
What to do if you accidentally cut your cat's whiskers: Sometimes grooming accidents happen, or children get too excited with a pair of scissors. But don't panic - your cat's whiskers will grow back, it will just take a while (approximately 2-3 months). Yes, your cat will feel a little disoriented for a few weeks. The only thing you should do while waiting for the whiskers to grow back is ensure you keep your cat indoors at night. They will mostly be fine to go outside during the day, but as nighttime often brings fights and predators, best to keep them safely indoors.