Blind signing: keep these points in mind:
1) Early signing methods like eth_sign can sign any hash, which may actually be a transaction. Some wallets have disabled it by default.
2) EIP-712 defines a format for signing structured data. Wallets that support it can display each item of the data to be signed, making it much easier to understand than a string of hashes.
3) Don't sign anything you don't understand, especially requests that show only a string of hashes without any explanation.
A quick look: $ETH reports 2348.65 (24h +0.81%).