If you want to build something for bitcoin community and you are a experienced web developer, you can make a stolen bitcoins database, where users can post their wallet addresses and a proof of ownership and it should allow them to explain how they lost their bitcoins and they should be able to track their funds or get notifications when funds are moved. If it works properly I think exchanges can use it's Api to identify stolen funds/deposits.
How this idea can help peoples?
This will be database only..
Yes, they can track stolen bitcoins, but they can't refund lost money.
I think this idea is useless (my opinion only)
Its true, useless 100% until you want to cry..listen Norah Jones that will work.