One thing that really infuriates me are websites that have something on them that is time sensitive that are not updated or have a "date created".
Today I looked on the Cambridge University weather page inviting me to meet them in September, except this was September last year! I cannot tell you how often I have read a webpage only to find it is years out of date.
So, the very least they could do is put a date saying when the page was created. Better, still update the webpage!