My guess is you have never found yourself in this kind of legal situation.
In my experience, as someone that was detained for the first time at the age of 14 by the secret service for counterfeiting, has multiple subsequent arrests, and despite all that actually became a lawyer myself, while a lawyer later in life was abducted and kidnapped at gun point managed to escape by jumping out of a moving car and tracked down the guy 24 hours later and delivered him to the police (or police to him) - so I feel I have some life experience - it’s the person screaming the loudest about what they would do in the shoes of others that is usually the least likely to actually do it.
Unless you can say what you have done in like circumstances you don’t know.
So before you go around championing marking people with tattoos in order to readily identify them, at least consider where in history that very concept comes from. My suggestion if you feel so strongly, is help, maybe by donating money for a legal fund, or at minimum show a little compassion and moral support, but don’t tell someone else what you would do in their shoes and how you’d punish them if they don’t show the same moral convictions you pretend to have without being put to the test.