Indirectly - all visible light is non-ionising and of much, much higher frequency than that used by telecommunications devices - and we have all of human history to suggest that light isn't dangerous.
I did some research on PDT as an undergraduate in university and the absorption of light by cells. I'm not in the medical field, but from what I understand most of the biological effects from lower energies just come from the heating of cells.
Wikipedia has a very brief chart on the biological affects of non-ionizing radiation: https://en.wikipedia.org/wiki/Non-ionizing_radiation#Health_...
And don't forget simple facts like bright lights can blind people. Blanket statements like "(non-ionizing) light isn't dangerous" often have holes in them.