Coffee can kill you if the amount exceeds the safety limit. The lethal dose of coffee for an adult is 100 cups of processed coffee drink or about 10 grams of caffeine over about 4 hours.
This fact is dependent on individual sensitivity, but is estimated to be about 150 to 200 milligrams per kilogram of body mass or roughly 80 to 100 cups of coffee for an average adult. So be careful about your daily intake. 😉