Earlier quoted context omitted.
Not that I don't agree with you, but it would be difficult to find such case - because most of the pages have the copyright notice. I am guessing that it doesn't hurt, so why not have one?
Most copyright notices on these pages are invalid, so they would not serve as valid notice anyway, so your presumption is wrong (it also reminds me of the bear patrol episode from the simpsons) First, the form is often wrong, which makes it the same as no notice. Second, if the date is wrong, it depends. If you use too early a date, you lose that many years of protection. If you use a date 1 year or more after first…
The best protection is that which helps to keep at least some unauthorized copying from happening in the first place, not that which lets the copyright owner (expensively) go to court.
Elsewhere in this thread, @lloeki is on the right track: https://news.ycombinator.com/item?id=8809137