Perhaps this is due to the fact that they lost the court and is now preparing to hand over to the tax authorities of their customers. If so then you have a problem. I think that if people find out about what data about them is transferred to the tax office they will cease to use this exchanger. They can go broke.
I highly think it's not the case in this one. As far as I know, Only financial records were handed over not an access to accounts. These records will be reviewed and if deemed suspicious IRS can ask coinbase to freeze/disable its corresponding account either temporary or permanently. The idea is to halt the user/s future transaction/s, this is impossible if they just withdrew his coins, to add on they are regulated and with this kind of act, it's like they are upfrontly stealing.
@OP, It's most likely the usual compromised wallet which often occurs on web wallets. There are various reasons on why this is occuring so think back on what you did as they might be a phishing link thet you clicked, malware, keyloggers etc.
Unfortunately there's nothing else that you can do since bitcoin transactions are pseudonymous and irreversible. A piece of advice for you is to change your wallet.
Web wallets are unsafe enough but it's even more unsafe with coinbase as it is completely centralized.
Heres a tl;dr of wallet types:
--Snip--
Safest:- hardware wallet: both reasonably cheap and easy to use
- airgapped pc: expensive and a little bit harder to use (you always have to transfer unsigned/signed transactions between an online and offline machine)
- Paper wallet: very cheap and very secure if generated in the correct way, but hard to use (you have to sweep and discard the paper wallet each time you use it, then transfer the remaining value to a new paper wallet)
Medium:- Desktop wallet: free, but you need a clean PC and you NEED to encrypt your wallet (using a strong passphrase). Virusscanners/firewall are a must have
Unsafe-ish:- Android/Ios wallets: I call these ones unsafe because it's harder to verify the wallet's signatures, many people know less about their phone's OS than they know about their desktop's OS, and phones can easily get stolen/lost
Unsafe:- Any wallet where you're not the (only) one in controll of your private keys. This includes exchanges and online wallets