In the UK, possession of these jammers is legal, but according to the law dating back to 1949, their operation is illegal! When the British authorities are more arrogant towards individuals than Blair's current traitor. It's difficult to deliver an order online in the UK or even an EU country, but suppliers from the Far East often 'fix' the problem. Otherwise, send it to a non-EU accommodation address - try out the hotel you 'intend' to visit, then move it home. For the British, remember that the Channel Islands are not part of the European Union.
And don't say "Oh what about emergency calls". I'm sure ten years ago hardly anyone had a cell phone and we've done a good job at this point. If others talk about their right to "communicate", don't we have the right to peace and quiet?
I am also annoyed by the phone ringing at inappropriate times, and annoyed with speaking out loud, so I think the existence of signal jammer is very positive.
There is another side of the story. My wife and I bought our first cell phone a few years ago. We are early adopters because we have a daughter who has special needs: her intellectually disabled person suffers from epilepsy and many other medical problems. When something happens to him, we have to understand immediately.
One way for us to stay sane is to ask the caregiver to take care of her when we go to the movies or to a restaurant. If someone calls one of our cell phone numbers (there are now two) we hope they leave a voicemail and we can listen to them after the movie ends.
Whenever we are in a sensitive state, we always vibrate the phone and turn off the ringer. If someone calls (this rarely happens) we will get up immediately and answer the call if we cannot hear it.
Now I know we are unusual. We use our cell phones primarily for emergencies and never for chatting, but we will be very sorry to hear that we have relaxed the facility and not let our calls be answered.