It's the modern generation, I'm afraid...
Have you never told your DD off and then had her sulk and tell you you screamed' at her?? We live in an interesting generation power wise, where children don't have the same automatic society bred respect for authority (I am aware I sound old fashioned!)
When I started teaching 20 years ago , I was admired because I could control a class. I did like a good shout. Some children thrive on being a bit intimidated. then that moved to be called a disciplinarian...
Now, if I mildly harangue a student, I get told (by the student) that I am 'shouting on their ear'
All part of the entitlement culture.
I think the police sometimes get this same allegation! And they have licence to be far ruder to their inmates!
There is an actual definition of 'screaming'. I am sure what you and DD actually mean is 'shouting very loudly'. The voice can be a powerful weapon...
(Disclaimer: I don't actually shout very much. I use it sparingly. Am fed up of adolescents sulking though when reprimanded, possibly because it is the first and only time any one has put them in their place, or sometimes because it reflects how they treat their parents)
If someone filmed an assembly , I think that is awful awful behaviour. Boy would I yell (not scream) at a student who did that.