alt Hacker NewsThe vulnerability of steganography is that is has to pretend that signal is noise. Remove the noise - and the signal is gone. I'm pretty sure that the simplest gaussian blur will remove the spymark from any picture.
Or... add some noise. Just align the last bit of every pixel channel with a random bit sequence - and Bob's your uncle.
"just" yes, you "just" have to do it every time. and so does everyone else. sadly we live in a society of comfort, where people do not even remove the trackers from links, so why would you expect they add a blur to images...