As the situation is getting intenser, free thinkers need a sign to recognize or just greet.
And so there is the dark dystopy “1984” of total control from George Orwell, which is fitting to be quoted.
There are multiple movies made, here is the scene from the 1956 version from Michael Andersons, which by the way is the mildest adaption of the book.
And so the new greeting or sign of recognition among the free thinkers is the hand with four fingers and a whispered (or loud) “Four.” It is like the new “high five”, but without contact, which fulfills state orders.
Also in Germany a very public known doctor (video is in German) suggested a “I am not your opinion”-sign at your hair, mask or hat: a little tinfoil ball on a rope.
Edit: It is now this sign: “true” in sign language “Hand on your heart – Resistance 2020”: