Don't use online wallets
Anything serious with online wallet what happen why you use " Don't use online wallets " . because I am using online wallet I want to aware about any issue with online.
Because of seccurity problems, there is always a risk that your account or the site can be hacked.
For online wallets (exchanges and casinos), you don't have the private keys for your bitcoin.
So, the site owner can take your bitcoin and vanish at any time, and this kind of thing has happened multiple times.
Blockchain.info is cool though, because the site owner doesn't have access to the private keys of the users.