For an analogy, suppose you wanted to rehabilitate some drug addicts in a bad part of town, and as a result, frequented that part of town, and bought books on drug dosages. If that could get you arrested because the cops couldn't tell the difference between you wanting to help drug addicts and being a drug dealer, and arrested you based on frequently being in the wrong part of town and showing an interest in drug literature, then it would send a clear message to go no where near these people in need. And that would be a shame.