So he was an active member.
Contributed several posts to your forum.
Then one day he decided that he no longer wanted to be a member.
He asked for his account to be deleted. Then he said you could continue to keep the previously posted content... he already gave to you.
As he asked for, everything related to his account profile was deleted, but the content he contributed to your forums, remained intact -- as "anonymous," so as to not destroy you forum's conversation flow.
Now he comes back and demands that you reverse his choice to have been deleted.
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I say, if you choose to, let him create a new account and use the same/similar name to what he previously used (if it's still available).
At the very moment that he said he no longer wanted that content or to be a part of your site, he gave up all rights to whatever he contributed to it.
When someone contributes their own unique conversation to your forums, it becomes your property, because you are that discussion forum's owner. There are no take-backs. If you have 50 people conversing on one topic, and one person leaves with only the words which he's contributed, the conversation flow is destroyed.
You had preserved those conversations by not removing the content, and also replaced the creator's name as "anonymous." The discussion flow is maintained. This is one way to handle things. It's not bad.
Personally, rather than deleting the account (it was not a spammer), I would have locked the account and noted on the profile, either "Banned"/"Deleted"/"Locked Account." Then, if the guy ever came back, I'd tell him that the policy is to never revive accounts and he needs to start a new account with whatever acceptable name he chooses.
Everyone runs their site differently. I personally don't like to delete these type of things. Paper trails are good for when people like to look back at why something happened in the past. They even sometimes remind us why they shouldnt be repeated in the future.
"Widespread online filtering will only increase distrust between people and the state." -Hassan Rouhani
