Question:
Answer:
Regarding mortal sin, remember that there are three components, including grave matter (the Catechism 1858).
Many images are posted online with the permission of the copyright owner without any impediment to their being downloaded and shared with others. Oftentimes, there is no name attached to the photo or other image, and there is the intention—sometimes expressly stated—that the images can be shared with others. In such cases, feel free to download them for personal use and cite the copyright owner and/or website if using them professionally. Such use is permitted under “fair use” U.S. communication laws and otherwise, in general, by the larger moral law, and is the online parallel to citing a work in a written article or book.
On the other hand, don’t sell such images without the express permission of the copyright holder. In addition, if the image has a copyright symbol and there is the express request that any use be authorized by the lawful property-right owner of the image, gain that permission before downloading.
A more clear-cut example of serious/grave stealing would be hacking into a website like www.gettyimages.com that sells the right to use high-quality photos and other images and then downloading the images and using them, whether for personal or professional use.
Unfortunately, in our society many feel that if you can copy or download something it’s fair game. Before the Internet, such piracy including the authorized copying of various software programs. Today piracy embraces the unauthorized downloading—for whatever use—of movies, music, etc.
Artists of various sorts make their living via their creation of images, and just because it’s easier to violate their property rights than it is to steal a car or TV doesn’t make it right. Steer clear of such immoral practices.
For more reading on this subject, see the Catechism’s treatment of mortal sin in general (1854-64) and of the seventh commandment re: stealing in particular (2401ff.).