I am tired of the crap from both sides on this one, I've historically kept away from the music section, so haven't had much input into any policy.
This is now the official fanart.tv policy on this subject.
DO NOT SOURCE IMAGES FROM ALBUMARTEXCHANGE PERIOD.
If an image is only available on AAX, here are your options:
1) Buy the album and scan it in.
2) Ask the original uploader if they would upload to fanart.tv as well, but ONLY if you are already on speaking terms with them or they are already members here, do not cold contact people.
3) Ask someone who has the album to scan it.
4) Go without the image.
I am not going to recriminate people for past actions as there was no policy in place, it was probably even implicitly welcomed as the quality of artwork from AAX is very good, but going forward it could lead to being banned for multiple offences (not everyone reads the forums).