And yes, they should be worried……
Prolonged Terror Alert at Delft University
The Technical University in Delft received a bomb threat on 21 November 2015, in the form of a message found in the bathrooms. The message was written in poor English, and included a sketch of a turbaned head.
The same day, several unknown bearded youths were seen photographing parts of the library, which also raised suspicion. Security measures have been and remain in place since the bomb threat was received over two weeks ago.