Although then someone might set up a mapping file saying "deleted-xS72d equals ptaipale" and 10000 similar records. It might be illegal in EU countries, but that doesn't stop it from happening somewhere in the US, or China, or South America, or whatever.

I've faced similar requests on a small board that I maintain, and there's no very good solution that wouldn't break the right of others to keep their own submissions intact and meaningful.