Someone asked about the right to free speech. It does not extend in this case any more than it would to someone screaming fire in a crowded theatre when there wasn't.
Females with backpacks are the en vogue weapon of choice in Israel for blowing stuff up.
I wonder how many would say it would be an over the top reaction to stop another British citizen Richard Reid for saying he had a bomb in his shoe as that sounds almost as comical as impossible.
This girl will get the scare of her life and be let go. Perhaps she will remember to read the placards at the screening areas.