If the creator has NOT registered the image (or other piece of work) with the Copyright Office, they can generally only sue for actual damages or any additional profits made by the person who infringed the copyright.
If the creator HAS registered the image with the Copyright Office (and any pro photographer will likely have done this) they can sue for statutory damages, for “a sum of not less than $750 or more than $30,000 as the court considers just” [Title 17, Chapter 5, Section 504 (c) (1)].
Not only that, but if the court finds that the infringement was wilfull (that is, if you used the image knowing that you were not allowed to, and especially if the copyright owner had asked you to take it down), “the court in its discretion may increase the award of statutory damages to a sum of not more than $150,000” [Chapter 5, Section 504 (c) (2)].
These numbers are for each infringement, so if you nick three different pictures, or post a picture in three different outlets, the court can award these amounts times three.
In order to qualify for statutory damages, the work must have been registered “not later than the earlier of 3 months after the first publication of the work or 1 month after the copyright owner has learned of the infringement” [Chapter 4, Section 412].
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