Yesterday I made a mistake. I had 0.00959084 in my blockchain wallet. I run a faucet so I sent it to faucet deposit address, 0.00939084 - 0.0002 fee. After an hour I checked the transaction and saw it has been pruned by the network, at this point I had 0.00925 (guess they took additional fee) in my account, I went through the transactions and found couple of incoming transactions still not confirmed, but the balance was showing 0.00925 (before blockchain updated its wallet, unconfirmed transactions add up in balance, but when you are about to send bitcoins only confirmed balance is shown) so again I sent 0.005 to faucet deposit with 0.0002 fee and today morning when I checked this is what I got,
https://blockchain.info/tx/294cff0ed9a011626f4344039160c52cab5b5d04faa03d0f91571c20252eb964
And surprise my wallet balance is now -0.00501604 so I guess a total of 0.0144 loss. I made a mistake with the first transaction, I did not check whether there are any unconfirmed transactions (if there are unconfirmed transactions why add it up to the balance while sending) and the second transaction was legit and still double spend. Would this transaction get confirmed? And more interestingly today morning I also got a authorize log-in mail from blockchain, someone tried to access my blockchain account.
.
Time: 2017-02-09 02:10:03
IP Address: 177.21.194.220 (Brazil)
Browser: Firefox 4
User Agent: Mozilla/5.0 (Linux i686; rv:4.0) Gecko/20001019 Firefox/4.0
So in summary, a case of double spend and might be a hacking attempt.