This article needs some form of comparison
Is 240mg of caffeine a dangerous quantity to consume in a 24 oz drink? This article might have greater credibility if the writer had explained that a 24 oz can of an energy drink is roughly four times more in volume than a standard cup of coffee but the caffeine content would only be the equivalent of roughly one and half to two cups of brewed coffee (depending on strength).
Perhaps the real difference is that if one were to consume say, four cans over the course of a day, that cold equate to 7 or eight cups of coffee; probably only dangerous to people predisposed to caffeine incompatibility.