I just discovered (about 9 years after the fact) that The Art Museum Image Consortium (AMICO) was dissolved in 2005. For a while AMICO seemed to be one of the major art historical image banks for teaching and research. Now they are gone, though they have kept a web site for archival purposes (see screenshot of entry web page above.)
I have written before about digital centres that have closed down, AMICO isn’t an example of a centre, but it was an important project which is now gone. I can’t find any discussion about the dissolution, but will look. In general, I think we need to learn from the passing of projects.