We used to think that someone having our social security number was an issue. Then we thought that having others track your cell phones was an issue.
We shed DNA just walking down the street; it is possible that they will be able to detect this DNA in the future in real time. At least they will be able to offer you a coupon for that coffee house coming up on the right as you walk down the street. And parents will be able to know exactly where the kids are 24/7. Hunting for missing people will become a thing of the past.
I've considered this before - my DNA is spread worldwide at this point as I've shipped stamps to dozens of countries on every continent('cept Antarctica) by now. Maybe someone in the distant future will clone me!
In this era AP (after privacy) it may be easier to commit some crimes like identity theft and easier to slander someone or something; but, I am not convinced it is equally easier to catch the preparators committing the crime. Fake news has been around since the beginning of politics but getting away with it is thankfully more difficult.
This opens up a new area of stamp collecting: stamps certified to be licked by famous people. A common stamp with a certification of a deceased historic person or celebrity could be worth as much as or in some cases more than their autograph.