Billy, your right. If your operating legally under FAR 107 and this guy brings you down.. then yeah I imagine there will be an FAA problem. I can see ALL kinds of unintended consequences with this sort of device. It's basically taking the law into your own hands at least right now. What if he downs a drone trying to get an eppi pen to a trapped accident/flood/storm victim and the victim dies. Then it's manslaughter. FAA not withstanding.. Here is what the FCC says.
Jamming Prohibition
The use of "cell jammers" or similar devices designed to intentionally block, jam, or interfere with authorized radio communications (signal blockers, GPS jammers, or text stoppers, etc.) is a violation of federal law. Also, it is unlawful to advertise, sell, distribute, or otherwise market these devices to consumers in the United States. These devices pose serious risks to critical public safety communications, and can prevent you and others from making 9-1-1 and other emergency calls. Jammers can also interfere with law enforcement communications. Operation of a jammer in the United States may subject you to substantial monetary penalties, seizure of the unlawful equipment, and criminal sanctions including imprisonment.