Doesn't matter because they already have code implemented years ago that attaches a unique id, and when you take screenshots it includes a unique watermark that is associated with the registered account, it was put in to curb the mod/admin forum leaking way back.
Doesn't matter if you use an extension on your browser etc the screenshot will still have the watermark if you
are logged in when taking the screenshot.
it's kind of like the transparent watermarks they have for printers/camera's etc.
https://en.wikipedia.org/wiki/Machine_Identification_Code