Because they are unforgivable.
The use of any one of them will--
Will earn you a one-way ticket to azkaban, correct.
Now, the ministry says you're too young
To see what these curses do.
I say different!
You need to know
What you're up against! You need to be prepared.
You need to find another place
To put your chewing gum
Besides the underside of your desk, mr. Finnigan!
No way. The old codger can see out the back of his head.
And hear across classrooms!
So which curse shall we see first?
Weasley! Yes?
Stand.
Give us a curse.
Well...My dad did tell me about one.
Hm? The imperius curse.
Oh, yeah, your father would know all about that.
Gave the ministry quite a bit of grief a few years ago.
Perhaps this will show you why.
[insects buzzing]
Hello.
Lovely little beauty.
[chitters]
Engorgio.
Imperio!
[gasps]
[students giggle]
[gasps]
Don't worry. It's completely harmless.
[giggling]
[gasping]
If she bites...
[groaning]
...She's lethal.
[draco cackling]
What are you laughing at?
[students laugh]
Get off!
[moody laughs]
Talented, isn't she?
What should I have her do next? Jump out the window?