Y'know those QR codes that are displayed everywhere these days? The square arrays of funny dots? Yeah, those.
Certain special codes will give your smartphone heartburn, or even a virus, if you photograph them.
And, here's something cute. Look up the EUrion Constellation. Modern document-handling equipment has government-mandated pattern-recognition features to prevent copying any document containing that pattern.
Well, not so long after 9/11, the brand-new Department of Homeland Security started pushing such things for digital cameras. There are patterns that newer digital cameras will simply refuse to photograph, and you'll think you somehow flubbed pressing the shutter button; there are also patterns that cause the camera to go out of focus, or that cause the camera's internal firmware to blur a region around the pattern.
So, for example, if you want to be anonymous... all you need to do is to get one of the special QR codes tattooed on your forehead. Since all surveillance systems outside of a few top-security government installations are built on commercial technology, the cameras will edit you out.
Actual government agents have such tattoos done in special infrared ink, not visible to the human eye (it's also woven into their clothing in various places). If you look at one of them through, e.g., night-vision goggles, though, you'll see the pattern. And, if you find the right tattoo artist, and know the right handshake, you too can have an invisible anti-surveillance tattoo.