So here's a question. Is seeing death in a Grimm's eyes really an irrational fear or a preprogrammed response to danger? With regard to Juliette and Adalind, we know Adalind saw Nick's eyes because she responded to him. Juliette would have seen the look when she woged and Nick drew the gun on her. Wesen would see that look as well.
The best way to frustrate a cyberbully is to ignore him.