The fact that the identities of Coinbase people are known, and apparently you can hire a hitman with Bitcoin. If you have any Bitcoin left. Seriously, though,

The fact that the identities of Coinbase people are known, and apparently you can hire a hitman with Bitcoin. If you have any Bitcoin left. Seriously, though, Coinbase and other online wallets and exchanges need to get with the program and prove they're not running a fractional reserve. Radical transparency is a big part of the answer, and it's much more feasible with Bitcoin's public blockchain than with the dinosaur monetary system.