You don’t control your private keys and you share them with a third party. Meaning the coins stored on a web wallet aren’t yours.
Yes it’s unsafe and not just from a hacking point of view.
If the service goes down or they decide to lock your account, you can’t do anything.
So should use a offline/desktop based one instead?
Published at Sun, 19 Feb 2017 00:05:40 +0000