Suppose a twenty year old has no cell phone and no computer and never goes online. To a smart law enforcement agency they would take a look at that person. That person is off the bell curve of normal behavior. It could be that the person is severely handicapped or has some rational reason for being out of step with the world but more likely or not they are trying to be invisible. I'll bet all kinds of criminals could be caught by simply examining eccentric ways of life of individuals.
But in the U.S., that's not how it works.
We have this thing called the Fourth Amendment that has been interpreted to mean that I have the right to be off the bell curve and live in eccentric ways without federal, state, or local scrutiny. The exception is when authorities provide probable cause that I have committed a crime or that there is evidence of a crime present in the place to be searched.
Just being different really isn't probable cause that a crime is being committed.
And of course I'm not naïve enough to think that's the way it always works in practice. But that's the standard that we, as citizens, are charged with vigilantly supporting.