I think that people shouldn't eat food and drink anything on the streets and in public transport. Because it's disrespectful to other people. Everyone has to behave like an intelligent person. Eating and drinking may cause vomiting (рвота) or just simple sickness. And it's also not good to eat in front of hungry person. Of course, you can't know if someone has problems watching the process of eating, so it's better to put up with your hunger and eat in cafe or at home!