Digital watermarking can track where data is being viewed or downloaded, and identify the IP address and the type of device doing it. It is not in widespread use, according to experts, and could in some cases have privacy implications. Advocates say while it doesnt prevent a data breach, it can let an organization that has been breached know about it almost immediately, instead of months later. The average data breach goes undetected for seven months, experts say, but knowing about it has enormous value.”]
Source: https://www.csoonline.com/article/2949852/when-stolen-data-can-phone-home.html