All the images should be around uploaded to the account to anonymous.
Initially the program used to import all the old wallpapers preserving the tags (oh god if we had to retag everything again) assigned all the images to me. There was a big fuss in 4chan for that and emails of complains -so- every single post before transition is assigned to Anonymous (aka Oyashiro-sama)

So well I know lot of people lost their post count but well, I also lost my post count of 20k+

The software should detect the files that have already been uploaded