C- capital (letters)
Capital letters can change the context of different sentences, it gives of a mean and angry tone, this is bad if you didnt mean it.
Capitals can be the cause of cyber bullying so people say that to clear the fact that it wasn't supposed to be in capitals :)
person 2- OMG DONT DO THAT.
person 1- dude............... i was kidding.......
person 2- sorry, nmtbic
person 1- oh okaay cool :)