How can importprivkey compromise wallet security when importing a publicly known private key? A question was asked on reddit over here which I gave a reply: https://www.reddit.com/r/Bitcoin/comments/3khrvm/how_do_i_use_private_keys_to_receive_bitcoin/

However, luke-jr replies with:


  Don't do this. You compromise your wallet's security to import a private key that others know.


without further elaboration. Can someone explain what he's talking about?
If Eve gives you a private key that contains Bitcoins in exchange for a pile of gold coins, she still has a copy of the private key, and can take the Bitcoins back, leaving her with both the gold coins and the Bitcoins.

Instead, tell Eve to send Bitcoins to your address.