Lately the Maxim-IC newsletter delivered to my inbox carried a link to an interesting document about Counterfeit ICs—the Serious Problem that Only We Can Make Go Away.
While as hobbysts we cannot do much about the phenomena, we are certainly pushing components to their limits and beyond (here I am thinking of the CW TX based on 74HC240 run at 7V, IRF510's as HF PA, ...): counterfeit components can be the cause of an unexpected failure.