[SemanticStrengh]

Is there a way to prove that you own an old bank account with X money in it? Or better, to be able to exhaustively list your bank accounts and their respective amounts? Well a salary bill pay document should be enough though if not falsifiable.

[blep_]

I expect not. Actual government agencies have trouble with that kind of thing (for taxation/fines/judgment enforcement); random hackers have no chance.