Facebook, Twitter, etc. to see their suspicious activities.
Make the spreadsheet private (because some members are posting private key because they're newbie)
or make a unique registration submissions.
This is what I recommended.
Agrees to both above.
1- Multiple social media account would not make the system fool proof, but at least harder for fraud claims.
2- I would say make the registration if the wallet address is unique. This would solve the issue with various people posting other's information in form with their ETH wallet addresses; as the owner of the unique wallet will receive only. Spreadsheets shouldn't be published at all. There should be a published and public page that fetches only minimum information; like wallet id and twitter account /bitcointalk id, and display as a webpage. To resolve issue of newbies posting private keys, the form /submission system should be smart and tight enough to allow only the wallet format or disallowing the private key formats.
My 2 Satoshis...