I used the blockchain wallet since I started with bitcoins more than a year ago. They email you for authorisation when a unknown computer wants to access your wallet. I have about 0.5 btc on there for a long time and it's still in my wallet. I think they are safe if you access your wallet securely.
Not really in the exact words of a Blockchain email Confirmation RequiredAn attempt has been made to login to your My wallet account from ip address 80.243.180.98. Enter the confirmation code below to access your account. If it was not you who made this login attempt you can ignore this email. This ip address took me for 17 Bitcoins as it says if not me that attempted i can ignore the email ... yeah right thanks Blockchain
