"Unauthorised use" refers to the act of utilizing or accessing something without permission or legal authorization. It means using or taking advantage of something when you are not allowed to do so. Full definition
Prince, an artist known for his work involving appropriating photographs, or re-photography, was sued for unauthorised use of Cariou s images. (artbook.com)
Now, once again, the artist and the Gagosian gallery, his former dealer, have been sued for unauthorised use of an image by Ashley Salazar, a model who originally posted the picture to Instagram. (apollo-magazine.com)
Although there are few banks that offer protection such as FDIC insurance and protection from unauthorised use of the cards, these are at their own discretion. (myfinancekits.com)