--snip--
So there's no way for that... Except "realize ethically" 
On purely technical level, it's definitely impossible. But on legal level, there are things you could try such as,
1. Asking log from the server, if you use wallet which connect to single centralized server.
2. If you ever withdraw Bitcoin from centralized exchange to your wallet, you can use withdraw history as proof.
--snip--
What if noone have tryed? Or has, but stayed silent! Someone have tried that. Few years ago, there's github user called "phutris" which fork open-source tool and TG group to crack "unused" or "abandoned" Bitcoin.