You cannot use a jammer of any kind in the United States, for almost all values of you, including state and federal penal agencies. https://www.fcc.gov/general/jammer-enforcement
https://www.ofcom.org.uk/spectrum/interference-enforcement/s...
There are after all good reasons to ban them, but even if those reasons didn’t exist, the Tories would ban them for their usual “law and order” reasons.