First of all, I mention this issue and many more serious ones here:http://www.peaktestosterone.com/Coffee_Caffeine_Dangers
Furthermore, in my link I clearly reference the above at the beginning of the page: "Coffee and caffeine have their scary side. For more information, read about The Potential Dangers of Coffee and Caffeine."
Also, the cortisol issue is actually hotly debated and poorly researched. Look at this natural news summary:http://www.naturalnews.com/034674_coffee_cortisol_weight_gain.html
"While caffeine prompts cortisol production, a 2005 study published in the journal Psychosomatic Medicine found that regular coffee drinking increases our tolerance, blunting this effect somewhat. Subjects in this study who were given caffeine after a five-day fast showed cortisol spikes in the morning; an effect which diminished after several days of regular exposure
. However, researchers also found that when subjects were exposed to caffeine continuously throughout the day, cortisol levels began to rise again in the afternoon. Further results also showed that study participants prone to high blood pressure reacted more strongly to the caffeine than did others and produced more cortisol."
Again, the issue with caffeine is that short term it has some very negative effects but long term the body adjusts very significantly.