There was a question asking about CC BY-SA 3.0's requirement to remove attribute on request. It was brought up that automatic archives may still preserve historical information, including attribution information. Two comments to an answer on that question were of particular interest:
"We publish data dumps of all the visible content on our sites. This is historical content and we cannot modify previous data dumps to also remove your name in those places." I'm interested to know how that aspect of the policy is compliant with CC. – fabspro Mar 20 at 10:19
@fabspro You should start by asking a new question about that. Most likely, there is a good answer that satisfies the CC license, while still allowing for historical archives. I would also be interested in an answer from a knowledgeable source. – JonathanDavidArndt May 14 at 14:56
Since it seems the question was never asked, I'm asking it here. How are historical archives made compatible with the license the content is under, since the license requires attribution be removed upon request?