Digital watermarking is a nascent but promising technology that offers protection of unencrypted digital content. This paper is a brief technical survey of the multimedia watermarking landscape. The three main technical challenges faced by watermarking algorithms are fidelity, robustness and security. Current watermarking methods offer possibly acceptable fidelity and robustness against certain types of processing, such as data compression and noise addition, but are not sufficiently robust against geometric transforms such as scaling and cropping of images. Theoretical approaches have been developed that could lead to secure watermarking methods, but substantial gaps remain between theory and practice.