Why are people so judgmental and what not on the internet?

[Brainy]

Now, I am going to ask about this website as an example because most of you may or may not know what other websites I frequent.

Anyway, I just wanted to know what is with these people? For example, I had a sick dog and we could not take her to the vet even if we could afford it because the vets were booked. I asked what helps a sour stomach and stuff for dogs and they attacked me saying I am an animal abuser and that my dog is going to die. Which they were wrong since she's alive and back to normal and was not even seriously ill.

This isn't just me of course. People jump to conclusions, add information that you didn't even say, accuse you of random and crazy things. Is there something wrong with people like this? I seriously think there is at times. So I am just curious as to why people like this feel so comfortable with doing this online. Do they not understand that there are other human beings behind these screens or something? Should they seek help? Maybe Y!A and other sites need to pay more attention and stop this behavior (uh oh! Did I just criticize Y!A? Oh boy, I shouldn't do that! Criticize Big Brother and you'll get suspended! Welcome to 1984. Excuse my sarcasm, couldn't resist an Orwell reference.)
Aw man, I'm sorry. How the heck did I get to YA Australia?! O.O