In past week or two, there has been 3 flights from Belgrade (Serbia), to Moscow, who got anonymously tipped via Email, that there is a bomb planted on that aircraft. Every plane immediately made a turn, and landed on the closest airport, so the passengers and stuff can be evacuated, and the plane can be examined. Each alarm was false.
So my question is, what can an Air company actually do in those situations? I mean, someone can send those threats on daily basis and cancel many flights by doing so?
Note: I'm really not sure what Tags to put.