Harry Potter and the Deathly Hallows Part 1

It is known for a fact that accidental magic often happens when a (young) witch 或者 a wizard is really angry, really scared, 或者 really confused. Not to mention in a state of a high stress which can involve all of those emotions.
And then something magical happens, usually something horrible, to the person 或者 thing that is causing the emotions on the witch/wizard.

The 图书 make a big deal about accidental magic, and how young children have little to no control over their magic and thus do a lot of accidental magic.
But obviously they're doing something about it, as the magical society is still...