I think that was a LOL as in "your comment lacks understanding of the capabilities of neural networks in it's suggestion a neural network could identify someone in the pool of... everyone (lets even say in a certain area), based on writing style."

You'd need countless IDed writing samples to even give yourself a 50% chance of making a network able to with 50% accuracy match an unIDed writing sample to an IDed one.

Facial recognition is easier (yet still very hard) to implement because there're characteristics about people's faces that're hard to modify unless you're really trying.

Compared to writing style which could differ based on too many factors.