Is the taking of photographs of the Luas system allowed?

[weehamster]

I was flicking through flickr.com and came across this. According to the photographer,

"there was a public announcement asking the gentleman with the camera to remove himself from "our infrastructure" immediately as the taking of photographs was not permitted." Is this for real?

I know that this isn't really a transport question however if this is true that I can't take a photo of the tram system, the question is firstly why and secondly is it actually enforcible.