Unauthorized use of images is defined as copyright infringement. In general,  U. S. Copyright law provides penalties for infringement which can include both "actual" and "statutory" damages. Because all of my photographs at this site are registered with the Register of Copyrights at the Copyright Office of the United States Library of Congress, both types of damages may apply. Other penalties may also be incurred, as noted below.

Actual damages can include actual losses (i.e. lost fees) suffered by the copyright owner, plus any profits realized by the infringer.

Statutory damages can include up to $100,000 United States dollars for each unauthorized use that can be shown to be willful.  "Willful" generally means any unauthorized use of a photo which the user knew was a copyrighted work (such as through the presence of a copyright notice, as on all pages at this site).