The only example I can think of is Facebook comments. I often zoom in on Facebook and leave it that way. I have actually seen this quite a lot amongst less pop

The only example I can think of is Facebook comments. I often zoom in on Facebook and leave it that way. I have actually seen this quite a lot amongst less popular websites, such as websites for local dental practices. I work for a marketing company in the UK and I've even seen our own contracted designer do this. If I don't do it myself, I'm often asked by the client to increase the font size. It's quite pervasive. xwl.me is readable and I like how it's very simple too. I might tint the background colour but not so much that it kills contrast between the BG and text. I notice my eyes feel scorched using editors with pure white BGs after some time and I'm not surprised; #fff creates the brightest light source for a monitor and it's never pleasant looking directly at a light or, more extreme, the sun.