Hermione straightened her papers and waited for her former professor to finish before speaking. "If I may?"
She paused until she was sure her voice wouldn't rise to adolescent shrillness in the face of so many of her old teachers. "It may not be as simple as finding a person or entity, I'm afraid. The incidents are spread widely enough, and enough people have been involved, that it would be almost impossible for an individual or a small group to be responsible.
"It also seems to be largely confined to Britain, whatever it is. I was out of the country for much of the winter, as were several of my colleagues. None of us had major problems when we were - elsewhere, only after we'd gotten home."