Can hardware wallets like Ledger Nano be hacked and their coins stolen?
In theory, it's possible everything including a hardware wallet can be hacked, but a hardware wallet is one of the safest ways to hold your coins. I have a hardware wallet, I don't fear it will be hacked, but I do worry about people somehow will find the seed words I have written down, and steal my coins that way.
Yes, it can be hacked if you are not responsible to keep your private key and password, everything of the gadgets uses has to engage online and having an internet connection then you are prone in hacking. Having a clean PC will help you to avoid the phishing site. For example that may lead you from hacking example malware virus which is entire