Everyday various internet sites report on violent attacks/sexual assaults in Europe, with a focus on recently arrived migrants:
https://gellerreport.com/2018/01/sweden-teen-sex-attack.html/
(Warning, this one has a shocking photograph, graphic.)
https://gellerreport.com/2018/01/sweden-war.html/
https://gellerreport.com/2018/01/denmark-muslim-terror.html/
https://gellerreport.com/2018/01/germany-women-safe.html/
https://gellerreport.com/2018/01/sweden-migrants-murder3.html/
https://voiceofeurope.com/2018/01/europes-hope-austria-joins-eastern-europes-anti-immigration-bloc/#.WnDG7xEjTyY.twitter
These attacks have led to a massive rise in small arms sales in Germany:
https://www.zerohedge.com/news/2018-02-01/arms-german-small-arms-ownership-soars-85-under-2-years
which I was surprised to read given the generally strong anti-gun nature of socialist Europe. Nevertheless, the fear is out there.