Is using signal jammers a dangerous idea?

Imagine: you're at the mall, talking to your family on your cell phone, and suddenly there's no sound, and you find your cell phone is dead, not dead. It's not because the signal is down or it's not expensive, it's probably because other people in the store don't want to hear you talking loudly! This makes it difficult for them to get a good environment.

Recently, a Philadelphia man, speaking on the condition of anonymity, told local television that he was using a "cell phone jammer" on public transport so he could be quiet. Now all the questions about whether signal interference is dangerous are: what is a cell phone jammer?

The mobile phone jammer is a device used to prevent a mobile device from receiving signals from its base station. The military cell phone jammer was originally designed for law enforcement and military purposes, so it may block communications between terrorists and criminals. They are also common in prisons, where cell phones are not allowed. Once the public is aware of the technology, many people - especially employers - want to use it themselves, especially in big cities, where everyone seems to be talking on the phone. With the popularization of smart phones, banning mobile phones seems to be a common prohibition point in many public places.
But how does a cell phone jammer work? I mean, it sounds like a bad science fiction movie, right? Well, they use antennas to send radio waves at the same frequency as cell phones. This leads to enough interference to render the phone useless in the area of interference (maybe 12 feet to 5 miles, depending on the type). The new equipment is small and often disguised as a pack of cigarettes. They're as bad for you as smoking! How's that？
In daily life, on the other hand, the use of mobile phones block seems to be a good idea. Who wants to sit next to someone on the train, to their doctors have said that they last a saddle rude details? Would you get more work in the library or at work if you stopped texting your best friend every two minutes? But when you stop to think about it, is using a cell phone jammer a dangerous idea?
Why? First, they are illegal in public places (though the FCC can waive the use of private law) because they can block emergency signals. The man on the Philadelphia bus might not have thought what would happen if, god forbid, his bus crashed and someone had to call for help. If your boss uses a cell phone jammer at work and your store is stolen, that's not a good situation!
How would you react if someone used a cell phone jammer on you? Do you think using a cell phone jammer might be beneficial or should it always be illegal? Leave the comments!