Laws do vary by states, unfortunately for nature in some cases. I do know that along the coastal areas of Maryland it is illegal to fill in any "critical" wetlands, be it your own property or not. This is to perserve the natural areas and help prevent runoff into the bay. The DNR have been known to fly along the coastline checking for changes in the amounts of wetlands on people's property.
If the property owner in question feels his bog is a nusiance, then perhaps he needs to check into having it declared a protected area and receive a tax write off for having a "nusiance" on his property.
BTW, the selling, shipping, etc of any "legally" protected plant must be accompined by paper work from the property owner proving that the plants were collected on private property.