alt Hacker NewsStylometry killed that a long time ago. There was a website, stylometry.net that coupled HN accounts based on text comparison and ranked the 10 best candidates. It was incredibly accurate and allowed id'ing a bunch of people that had gotten banned but that came back again. Based on that I would expect that anybody that has written more than a few KB of text to be id'able in the future.
You need a person's text with their actual identity to pull that off. Normally that's pretty hard, especially since you'll get different formats. Like I don't write the same way on Twitter as HN. But yeah, this stuff has been advancing and I don't think it is okay.