On December 23, Binance co-founder CZ tweeted yesterday,"Recently I have seen some people collect cryptocurrency by accepting private keys or hardware wallets. This is a bad idea because the donor still has access to these cryptocurrencies and should transfer the cryptocurrency to the address he owns, or better yet, just have the donor send it to the address he owns. Letting two people access the same private key (or mnemonic) is a bad idea. When these encryption is moved (or stolen by hackers), it is almost impossible to prove who moved it (or hacked into). "