If someone verifies to level 2, then empties bank account, instant buys 50 btc, then never pays, how can this be stopped? Cpinbase takes 2 days to take the bank funds....but they give 50 btc instantly? Sounds like coinbase open to get scammed.
To get "Verified, Level 2", they essentially get your personal info. If you attempt to scam them, they know who you are and will go through approved venues (collections, etc) to get their money back. It's why they can do Instant BTC, they know who you are and where you live.