The poster I responded to was talking about two seperate things: 1. Linking an image: Here no, copyright probably doesn't apply though attribution would be nic

The poster I responded to was talking about two seperate things: 1. Linking an image: Here no, copyright probably doesn't apply though attribution would be nice. 2. Copying an image to your server and serving a scaled version, or a complete duplicate of the original. Here copyright applies.