How MaiPDF protect PDF from screenshot

ScreenShot Prevention: The creative idea
Developers From MaiPDF is Smart and Creative
We use a patented solution of "Hold to View",which means the content of pdf file will be grey out unless you press the "MaiPDF" button at bottom left corner.

Suggestion From MaiPDF
Why is this feature help your PDF files from ScreenShot. Because once somebody hold a Button to read the file, how can someone take another hand to do the screen-shot?
However this cannot 100% secrued your file from ScreenShot. Like everything else on the Earth, if it is made by Human being, their is a flaw, obviously or veilded!