WOW!! Sorry to hear that!!

I would remove the app on your phone because I also have heard of an error with Android and a back door hack that allowed access to peoples phones which in turn caused others to lose bitcoins.
I am surprised about Coinbase.......use them as well and chose them because they are U.S. based.
I hope karma works in your favor.........bad luck to all the bitcoin theives out there!! It is a shame people have to steal.
Yeah - over dinner I tried to explain BTC to the wife and why it's not like the bank or PayPal that I can simply call and dispute the transaction. After a few moments she asked why I wasn't totally pissed about losing $3k... I couldn't do anything but chuckle about it. That's not to say I'm not pissed, but no use staying mad about it. This does mark the first time I've been jacked on a financial transaction via the internet - talk about crap timing. I'm trying not to be discouraged about BTC, but I'm just sitting here scratching my head as to how I could've better protected myself.
I thought coinbase made it now so that you need to enter 2 factor authentication code before sending coins out.
I turned on 2-factor authentication with Authy, and I did turn on my API to run a Windows app (Bitcoin Tradr) so I could have a running ticker on my metro panel. I completed all the verification steps with Coinbase so I could start instant purchases down the road. Also, I downloaded the COinbase app to my Android phone.
You'd think - but assuming that access was obtained via API, then apparently there's a loophole there. Again, I make that assumption because the network activity per their website shows nothing but just my IPs logging on since the account was created. I don't keep my Authy codes laying around (write them down, screenshots, etc.) so the only other access weakness could be the Android phone? I wouldn't even know where to start. That's another lesson learned I guess is never engage in BTC transactions via smartphone. Until Coinbase responds with more information, I don't have much to go on and it doesn't sound like the web app developer has any method to audit or recall transactions (or if they do, they haven't expressed any interest in doing so).
Bah...