Digital watermarking revolutionizes the fight against online piracy

Before watermarks, investigations began at the retail outlet, and copies were traced back from there. Now it is possible to go right to the source of the first theft. Watermarking involves placing on every copy of a film an invisible mark that distinguishes it from any other copy. The mark must be resistant to removal and survive multiple copying and recording processes. This robustness allows the watermark to be used for "forensic analysis," the process of tracing the specific content that served as the source of subsequent bootleg copies.