One think you simply cannot lock them against is screen grab software. Which makes it as easy as pie to copy images from a site.
Your best plan is to watermark the images, so that they are not (sensibly) usable.
What is ransomware and how do I protect my PC from WannaCry?
Disney layout supervisor Rob Dressel on the challenges of visualising Moana
Siri vs Google Assistant
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.