Hacking of Exchanges now and then: How safe are our private wallets

[lamby]

Exchanges like youbit and Etherdelta has been hacked recently. the questions begging for answers are:

1. how safe are our own wallets.

2. Is it possible to have our own wallets in our own phones and laptops hacked even though we didn't give out our private keys knowingly or unknowingly.

3. Is there a danger in filling ICO forms with our public wallet addresses (even though we didn't give out our private keys).


will be glad if i can get some concrete answers from people who really know.