It can happen to anyone, really. From time to time I
try to go through any sites I link to, and when I find them down (that is, accessing
it gives an error) for some time, I will add a text saying so.
Since the address of removed sites become available
to use for anyone and I don't want any unpleasant surprises with what the future
owner of that web-address plans to do with it, I'll unlink the sites if I'm
confident they're down, however still leaving your logo on the site. Even though
I would most likely not remove it anytime soon in that case, it would be kind
if you told me your new web-address (if you have one), so I can bring the section
up to date and relink you.