But law enforcement experts say its new popularity is especially frightening because it is taking place in an increasingly violent and criminal society.
Concerns about terrorism and news reports about sales of gas masks can be especially frightening.
Professor Feller described several instances when he narrowly escaped being caught and said they were especially frightening.
"I think people see it as interesting, but not especially frightening."
It is especially frightening because it often strikes younger women.
The early stages of dementia are especially frightening.
Several critics have praised Pearson's performance as especially frightening.
It was especially frightening to this man, Shef realized, because he had never felt such a feeling before.
Something about revisiting the dead was especially frightening to humans.
I found this especially frightening because in some ways it reminded me of my experience on the bus ride home.