I recently visited a site from HN on my phone, but its text was a bit too small for me to read, so I tried zooming in. To my surprise, it didn't zoom at all! From this article, the website must have set user-scalable=no.

I don't really see the point of this option. The website can (presumably) scale to many different devices already, surely it can then scale with zooming as well. I'd think you could use percentages to create any kind of 'static' ui, if you really wished to do so.