"The IWF manages a filter list that British ISPs utilize
voluntarily (I think -- it is hard to get a handle on it) that
block access to "illegal" content. In this case, the IWF says that
this album cover and associated text is "potentially illegal child
sexual abuse image."
"The album is a 30 year old recording by the Scorpions called
"Virgin Killer." The album, released before the 1978 Protection of
Children Act has already been modified once because the band was
notified it might violate laws in some countries.
"Wikipedia is upset because this is the first case where content
on its site has been blocked in the UK and it feels it is being
unfairly targeted because the album cover was still available as
part of the band's box set and could be viewed on retail websites
and When [Wikipedia] asked the Internet Watch Foundation why they
blocked Wikipedia and not Amazon, apparently the decision was
'pragmatic', which we think means that Amazon had money and would
sue them, whereas we're an educational charity."