Comment by saghm

I feel like a similar thing happens in "real life" sometimes, not just on websites. Back in high school, I used to volunteer at an animal shelter, and we had an area out back where we'd walk the dogs or let them run around in one of a few fenced in areas throughout the day so they could go to the bathroom and get some exercise. The door leading out here was located in one of the rooms with dog kennels, so people coming to potentially adopt a dog would walk through this room a lot, and often they'd try to walk out back and watch or participate with the volunteers and staff taking some of the dogs out. We'd ask them politely to go back inside because they aren't allowed out there and point out the very large sign in large font on the door saying this, and every time they'd always act very surprised because they claimed not to have seen it. I'm sure some people were just feigning ignorance because it seemed easier, but the sheer number of people claiming it makes it believable that at least _some_ of them genuinely didn't notice; they saw a door, they wanted to go through, and they opened it without processing the words right in front of their face.