Back in this post, I talked about doing design work for a video game company that when I showed my design work, I was told that the company expected me to do work on 'spec' for them.
A number of designs I had decided to put into a comic book page format, which included character design, the futuristic city environment design & robot design. Again, I had a very positive response from the supposed client, right before they told me that I would be working for free.
I declined.