This is the kind of thing, in my opinion, that an organized advocacy group could and should really help assisting the Geocaching community. In amateur radio, it's the ARRL, for example. For Radio Control Aircraft it's the AMA, etc.
If not Groundspeak, then perhaps a TXGA-like organization, that takes on the communication role when dealing with agencies that have uninformed employees. IT seems to me the armed, badge wearing type agencies (among others) have members that are quick to err on the heavy-handed side of things they don't understand. They often fallback on using intimidation, if not inconvenience, tactics and wielding authority or rights that simply aren't theirs. But, most of us aren't generally prepared to challenge this on an ad hoc basis.
Face it, when a cop is tailgating you on the freeway, no matter how fast you're going, most will move over ASAP. When an agitated officer tells you to scram, most sober people oblige with little push back. Most of us cannot afford to miss after school pick-ups, or other work / personal commitments trying to offer some officer education that leads to a few hours in the penalty box or the hoosegow! You may have been right, but that's small consolation for most, I suspect.
It's easy to say "go educate them" but IMHO this is bigger than asking a property owner if we can hide a log on their property. It's too bad we don't have an organization that is setup with expertise to deal with this kind of thing as a large part of their charter. A kind of geoCacher's Rights advocacy group. Maybe someday.
Why am I all sweatty and late? Umm...