My friend had a similar experience:
TVA’s private security detained our friend as (TVA’s words) an “environmental activist.” Cathy asked last night, what does one fear from an environmental activist at a toxic waste site? Are they afraid they’ll pull out a paper towel and start cleaning?
TVA’s private security, described as dressed in dark uniforms with no clear insignia, took our friend’s picture, took personal and professional contact information, recorded the license plate, commented on the contents of the vehicle, commented on the environmental bumper stickers, and kept our friend detained in the car for a half an hour. Our friend had turned onto a side road but not crossed any fence, barricade or posting of any kind.
Read more about the Tennessee coal sludge spill on Wikipedia.