Various cases of NPD online. The NPD-afflicted individuals usually are too arrogant to study or do anything difficult where they can measurably fail, and instead opt to blog on the topics where they don't know the fundamentals, promoting misinformed opinions. Some even live on donations for performing work that they never tried to study for doing. It's unclear what attracts normal people to such individuals, but I guess if you don't think yourself a supergenius you can still think yourself clever for following a genius whom you can detect without relying on such ordinary things as credentials or achievements, as described here.