With the new stricter labeling laws...

that is the statement you will find on many foods now.

There is a program, on the Science Channel called How It IS MADE...

and I have watched it some. You can see the dust that grows from making
crackers, coucous..etc. There are very few plants that can afford a
dedicated building that processes NOTHING else. The costs of those machines
are just so high!

Penicillin for example is made in a separate building at the drug companies, because minute amounts leak almost everywhere. And penicillin is so allergenic that this isolation is a must. And all good drug companies now have dedicated buildings for sterile products, for the same reasons. I can recall many years ago seeing in tours, just one corner or floor dedicated to sterile products.
But no longer!

So when it comes to cross contamination with foods...it will be harder and harder to prove...rigid GF standards, I predict! I suspect we eat far more crosscontaminated foods than we ever suspect!