Can hardware wallets like Ledger Nano be hacked and their coins stolen?
It's not easy to hack a hardware wallet, unless of course you give your keys to someone.
If someone gains physical access to your hardware wallet, I also wouldn't be so sure... at least set up a reasonably long/complex passphrase if you're using Trezor for bigger amounts of money and are taking it into account that someone could gain physical access to it.