I’ve always found it fascinating that people don’t perceive socially sanctioned drugs as drugs at all. Saying “drugs and alcohol” to me is like saying “sandwiches and hamburgers”. A person can drink a cup of coffee in the morning, smoke a cigarette on their lunch break, and drink a couple glasses of wine in the evening, and the only thing that keeps them from being called a “drug addict” is that these particular drug…
Coffee served at starbucks is in much lower quantities and milder concentrations than what one would normally ingest or inhale in harder drugs. They do boil tea out of coca leaves, which normally has a small amount of cocaine. It's only when it's concentrated, snorted, that it gives the temporary super high.
A common dose of LSD is about 50-150 ug (ug as in micrograms). A Starbucks Grande Coffee has 330mg of caffeine inside. That is THREE orders of magnitude!
So, to sum it up: you can't compare dosages from different substances.
Also: 330mg is a lot of caffeine.