Not only does this look dangerous to drink from, it's probably also really unsanitary.
This is a way more valuable message than the 'danger, rockslides ahead' message that existed before it.
Can you prepare full meals and plug in dangerous utensils on the subway? Do you even need to ask that question?
This man is drunk, but he could also be a vampire. Vampires sleep standing up, right? Regardless, watch out!