"So are the people who are talking too loudly on their phones, they are imposing their will on us without asking permission."

It is not about asking permission. It is about imposing a standard anonymously without recourse or appeal. The person talking on the cell phone is not anonymous. You see them, you can talk to them, you can treat them like a real person. And you can ask them to talk quietly or step outside. Direct, honest communication.

A cell phone jammer is incredibly passive aggressive. Instead of (politely) telling someone they are being too loud (which happens with or without cell phones), you sit back anonymously and impose YOUR idea of what right is. How is this any different than internet trolling? People are far more willing to do and say things they wouldn't do otherwise when they think they won't get found out or caught. This tells me that, on some level, they know their behavior is probably inappropriate.

As for the issue “If you have a chronic health condition and need a cell phone how would you use it?” Just because YOU can't think of an instance where that would be true doesn't mean it doesn't exist. An even if the person who has the condition can't use their phone, what about people around them? If someone is having a heart attack, or is seriously injured (in a fall perhaps) how much more time is it going to take to get a first responder onto the scene if everyone's cell is jammed and nobody can get through?

Like it or not, cell phones are with us to stay. Like any other technology they can be used responsibly or abused. More often than not, the solution is to be a responsible adult, treat people respectfully (especially if you disagree with them) and use direct communication about the issues at hand instead of attacking someone from a hiding place.