The easiest way in determining Fair Use, is to answer two questions: Is the use you want to make of another's work transformative -- that is, does it add value to and re-purpose the work for a new audience -- and is the amount of material you want to use appropriate to achieve your transformative purpose?
Examples of transformative purposes are criticism, commentary, news reporting and parody. If it is for non-profit, educational or personal use, even better.
Some commercial settings are also allowed under Fair Use:
Using a small image of a poster to illustrate a timeline.
Creating a parody of a song.
Scholarly criticism that quotes to illustrate a point.
A model's glossy photo used in a news report.
All of these are examples of cases where commercial uses of an appropriate amount of another's work were found to be fair uses.
You need to establish that your use is factual and published to make fair use of another's property as well. Imaginative and unpublished works are usually not covered, but a mixture of factual and imaginative will lean towards Fair Use.
One last question you may want to answer as well: What effect would it have
on the market for the original work?
If your use isn't transformative and actually takes away value or demand for the original, you probably can't claim Fair Use. Only in instances where the use is of very small quantity will non-transformative use be allowed.
So, let's use some examples similar to those mentioned at the beginning of this article. I will use the same photos that were claimed in the DMCA's:
With this photo I could report the event or circumstances that brought about it being taken. Or I could criticize the views that they share. If I were any good at humor, I could simply create a parody of their relationship. All for a good laugh. As far as I'm aware, this isn't a commercial photograph and does not contain any value, at least none that can be lost through re-use.
How about this one:
Same as above. I may be doing a blog post regarding Amy Roth. Attaching this photo of her to the post would be allowed under Fair Use. I may want to claim, in jest, that she gets most of her creative inspiration from female Jesus. (I told you I wasn't good at humor) It doesn't matter, I'm using it within the Fair Use guidelines.
Filing a DMCA complaint because you don't like how someone uses your work isn't enough to claim copyright infringement. You really do have to show cause.
I'll use one other picture from Amy Roth's site since this is about copyright infringement:
Pac-Man is a very recognizable icon. I'm sure Namco watches for any unauthorized use of its characters very closely. Using the above information, would anyone care to opine as to the legality of using these figures in a commercial venture without acquiring a license?