On Monday, Dutch police arrested the 14-year old girl who calls herself "Sarah" on the site after she sent a tweet to American Airlines Sunday.
It read "hello my name's Ibrahim and I’m from Afghanistan. I'm part of al Qaida and on June 1st I’m going to do something really big bye"
The girl later apologized, but it was too late.
“It clearly forces authorities to spend time and manpower to track down these individuals to assess whether these threats are real or not,” said Brad Garrett, ABC News Consultant, Former FBI Agent.
The incident is now attracting internet copycats. Dozens of threats are being tweeted to airlines.
Every one will be tracked down by the FBI.