Recently New York Magazine published an amazing story about a Stuyvesant High School student who had purportedly made $72 million in the stock market. When I read it I was pretty sure it was nonsense as in fact it soon turned out to be. As the magazine admits its fact checking was obviously inadequate. I expect this was caused in part by a failure to realize just how unlikely this story was and the implications for the appropriate level of fact checking. Suppose for example that there are a million false claims like this for every true account. Then fact checking sufficient to catch 99.9% of the false claims is totally inadequate as 99.9% of the surviving claims will still be false. As the saying goes "Extraordinary claims require extraordinary evidence".
New York Magazine stated:
... As part of the research process, the magazine sent a fact-checker to Stuyvesant, where Islam produced a document that appeared to be a Chase bank statement attesting to an eight-figure bank account. ...
But this is very ordinary fact checking. Anybody can fake a bank statement. The whole point of a bank reference is that you can verify it with the bank. If New York Magazine had insisted on doing this they would likely have avoided this fiasco.