This is how humans behave under anonymity, towards an anonymous crowd of people. It is something you don't see on the streets with the exception of a few assholes, but you see it a bit more on the road, where being in a vehicle puts some distance.

It is not a lack of shame and the treat of consequences. Take soldiers for instance, instinctively, they don't want the enemy they face dead, it takes a lot of conditioning to have them kill without hesitation and it often results in mental health issues later. And solders are rewarded for killing the enemy, it means the shame and threat of consequences go the other way. Normal people just don't want to hurt others.

But the more detached we become from the actual person, the easier it is to be an asshole. This is what happens on the internet where people are just entries in a database, at best a name and an avatar.