You could bring it to a large festival or even a protest. Law enforcement deploys them all the time. I found one using SnoopSnitch on an Android phone while at a large festival here in Louisiana.
Does that work by comparing known cell sites to found cells sites? I know some StingRay detectors use that method and it's prone to false positives around large events where mobile carriers or 3rd parties bring in legitimate temporary cell sites to improve cell service at the venue and provide more capacity.
