My good Oxford dictionary says:
I would further conjecture that "known" by itself implies "human, or possibly non-human, mind".
So, I would assume that data depend on minds while facts do not necessarily.
Well, that is all well and good, but discussions about the fundamentals of data and facts should be conducted carefully. I can see how it's possible both to consider photons as data or to consider them as facts.
Still, we can have a sensible conversation if we remain alert to the fact that we can maintain the distinction between photons as data and photons as facts: Very simply, we just have to keep in mind that some facts about photons may be unknown, and therefore not data. And then not go pretending we know these unknown facts.
A bit of caretaking is just what we need.
That being said, I would commend fast's careful style and condemn fromderinside's slapdash one as unhelpful.
Such is my mood today.
EB